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Interview of Frederick Seitz by Lillian Hoddeson and Paul Henriksen on 1981 January 27, Niels Bohr Library & Archives, American Institute of Physics, College Park, MD USA, www.aip.org/history-programs/niels-bohr-library/oral-histories/4877-2
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Family background and early education, motivation and funding for college; math program at Stanford University, from 1928; physics studies at California Institute of Technology; graduate study at Princeton University, beginning 1932, atmosphere of the department, faculty (Lou Turner, Eugene Wigner, John Von Neumann); colloquia, Edward Condon. Development of applications of group theory, work in solid state with Linus Pauling, Hillard B. Huntington, Albert Sherman, William Hansen, William Shockley, Robert R. Brattain, R. Bowling Barnes. Betty Seitz; work with her on the text Modern Theory of Solids. Sodium band theory work with Wigner. To University of Rochester with Lee DuBridge. Centers for solid state work including University of Michigan, University of Wisconsin, Harvard University (John Van Vleck). Work at General Electric, 1935-1936, studies of luminescence; atmosphere in industrial labs following Depression, contacts with other industrial labs; association with DuPont. State of physics in 1930s, trends at solid state centers. Work on crystal defects, pigments, leading to work on germanium and, particularly, silicon; history of study of semiconductors and influences on its development such as World War II; work on dislocations and creep; work at Westinghouse Company. World War II work with Frankford Arsenal, Dahlgren Proving Ground, and Massachusetts Institute of Technology Radiation Laboratory; University of Pennsylvania, 1938; Carnegie-Mellon University, 1942, on dark trace tubes, leading to color center papers; University of Chicago work on reactors and neutron diffraction, 1943; Oak Ridge National Laboratory with Wigner; Argonne National Laboratory, solid state group. With Field Intelligence Agency Technical (FIAT), visit to Gottingen, 1945; state of solid state physics in international centers and U.S. Return to Carnegie- Mellon; diffusion theory. Pugwash Conferences; trips to Japan, 1953 and 1962, conditions and theoretical solid state work in postwar Japan. To University of Illinois, 1949 (Wheeler Loomis); John Bardeen's work, visits by Nevill Mott and Heinz Pick; McCarthyism. Development of Seitz's bibliography, changes in the study of solid state during the 1950s.
This is Session 2 of an interview with Fred Seitz and today is January 27th, 1981, and we're at Rockefeller University in New York. So now you remembered some names of people who worked on copper oxide.
Yes. One of them was named Wilson. Re was in charge of the laboratory group. I forget his first name. The other was Rein, I believe Carl Rein.
This is at Westinghouse?
Yes, this is at Westinghouse, the group working with copper oxide. I don't know what happened to them. Of course, after the war or after 1950 copper oxide fell into a completely secondary position. But I lost contact with Westinghouse after I left Carnegie-Mellon, so I don't know.
Now, I seem to have lost a page I took notes on about your work at, what was it, Philadelphia Arsenal?
Frankford Arsenal, yes. Why don't you give me some information about that?
Well, in the fall of 1939, a group of scientists who had been taken on in the last year or so at Frankford Arsenal asked if I would be willing to consult with them. I was at Penn then, and I did. It was about an hour's ride on the elevated or maybe a little less. Used to go there an average of once a week. They had a very good program going. The director of the laboratory was Herschell Smith, and he had a number of colleagues with him. The group in fact eventually grew to a considerable size. They were interested in a whole range of things, from conventional metallurgy of ordnance equipment, to certain phases of optics. They happened to be given responsibility for optics. I worked with them on and off for several years on that basis. It also got coupled into some work at the Dahlgren Proving Ground of the Navy. A very distinguished physicist,Leonard Loeb, from the University of California who had been in the naval reserve, was made director of research there, pulled together a laboratory. A number of his students from Berkeley had been in the reserve, and he got them all to come. One of them was Norris Bradbury, who eventually was director of Los Alamos. Quite an exciting group.
Who were some of the others? Do you remember?
Well, Admiral Parsons, who flew the first bomb, was there at the time. He was what was called proof officer. These people were then very junior grade — it was about 1940 or ‘41 — in the Navy. He rose very rapidly, came from a naval family. And another person was Rob Varney, who's somewhere on the West Coast now. He was a physicist at the University of Washington, St. Louis. Oddly enough he'd been in my brother's high school class at Lick-Wilmerding way back when. Very brilliant student at Berkeley. As I remember, he graduated from Berkeley with a PhD at age 19. It was a congenial though spirited group, because Leonard Loeb was a rather tempestuous person. He got fed up at some stage and got another appointment out on the West Coast. But they had an interesting experimental test range for naval armament, projectiles. One of the things I used to do is get the people at Frankford Arsenal, who had full production facilities, to make projectiles, and I would take them down to Dahlgren. It was all outside the normal circuit of events, but it was the way you did things. About midway in all of that, OSRD was set up and I was asked to join. It was the so—called Division 2 of NDRC which became involved in ordnance. I spent about two years on various solid state metallurgical problems connected with ordnance.
Do you think you could list the problems you worked on at both these places?
Yes, let me do that on a sheet of paper some time.
You could do is add a footnote to the transcript.
They were very conventional problems, nothing very exciting. In the meantime the Radiation Lab at M.I.T., recognizing that the silicon diodes were essential to the operation of radar, began that outreach that I mentioned yesterday, to get people to work on silicon diodes. That's how I got into that.
I noted that George Sachs and Cyril Smith worked with you during the war.
Yes. George Sachs and Cyril Smith came to Frankford Arsenal occasionally. George was on a contract. One of the ailments suffered by the cases of projectiles was the development of what we called season cracks. These were the result of a combination of corrosion and residual stresses produced in the drawing operations. He was an expert at that and did a good deal of work on the question of learning how to anneal the shell case so it wasn't too soft and yet didn't have a large residual stresses. Cyril Smith was then working for one of the brass companies, I think Chase Brass. There was great demand for brass for shell cases, and he used to come and discuss quality and so forth. That was the first time I met him. Later on he went to Los Alamos and became an integral part of the scientific community.
Was he at the Met Lab?
If he was at the Met Lab, it was for a short period. At Los Alamos he worked on plutonium.
Now you also got a letter from Klaus Fuchs at that time.
Before he went to Los Alamos.
One of my good friends at Princeton, a Canadian, wrote a letter — it would have been about 1940 — saying that there was a physicist in detention in Canada who was without any access to scientific literature. As I remember I collected a fund, and we sent him the key journals of the American Physical Society, the PHYSICAL REVIEW and a few other things.
Just to educate him?
Well, to give him access. He was already well known. I knew him through the literature. He had worked with Born and then I think with Mott in England. He was a solid state theoretical physicist, pretty good background and had gone to England. He did not stay in Canada long. I forget whether he went back to England and then was shipped to Los Alamos with a group of Englishmen, or whether he went directly.
Now, by this time the big book you and Betty had been working on was out.
Yes, that appeared about 1940.
Was that used widely during the war?
Well, they sold out the first edition, and they got out a sort of cheap wartime paper second edition. I think on the whole, somewhere between 10 and 20 thousand copies were sold, a lot of them during the war, but most after. So it was pretty popular, because there were a lot of libraries being built up then. People began to get the money again to build up their libraries. I don't know what fraction of them went to libraries, but it became quite popular.
Did you hear how the book was used? Did it become the basis of new courses which were established? Most of these would be have been established after the war.
After the war, yes. I think mainly it was used as a sort of a reference work. People who would study on their own.
This was the first time there was a book with everything in it.
It tried to be comprehensive. I think Bethe had written an article in the old RANDBUCH.
That's the Sommerfeld—Bethe article. But it was limited to the electron theory of metals.
Metals, yes. I guess Bethe at that time was the equivalent of a post—doc with Sommerfeld.
And I gather he wrote most of it, except for the first section. That was widely read, but was in German. I don't think that was ever translated. It was quite a different kind of thing to read than the book which you presented, which is completely clear.
I tried to be as comprehensive as I could for the day. Of course, it looks pretty primitive now, but it's 40 years old.
It is still used very widely.
I think McGraw—Hill sold the publishing rights to the Indians, and they probably produce it for some international market. I don't think it's available in the United States any more.
I haven't tried to buy it. Illinois has about 20 copies in the library.
Well, Kittel kept his books up to date and they were very useful for the classroom. It's somewhat a standard text.
Is there anything else we need to say about this book that we haven't already said, either now or in the discussions in Santa Barbara? 
There are reflections in it of Wigner's lectures, although they are greatly expanded. You know, what he would have said in a couple of days would be expanded to a chapter. Particularly the early part. He was always interested in the empirical aspects. That was the chemist in him.
Do you remember how you began when you were organizing the whole thing? You started from Wigner's lectures perhaps?
No, I was at Rochester and gave a seminar, and it started there.
And it built out of those lectures.
Out of those lectures.
And what role did Betty play other than editing?
Well, she was a great help in testing consistency, collecting references and so forth, and she loved, strange as it seems, to check over equations. There are still a lot of errors in it, but a lot less because of what she did. As I said earlier, the book should have been published as a joint effort.
It's an enormous book. You wrote a second book during the war on the physics of metals.
That was a little book that came out of some lectures I gave to metallurgists at night.
These were evening lectures in Philadelphia?
Yes. Penn had a night school. I was asked if I'd give a night course. I think I gave it for one year or maybe two. A number of metallurgists from around town came to it. I don't know, I probably had 30 in the class.
How did that book do?
That did well.
It's very clear.
I don't think that ever got printed on good paper. I think the only copies were on sort of blotting paper. 
I have it out of the library. I'll have to go and check when I get back to Urbana. So you started the silicon studies, rectifiers. And the other big centers for study of silicon and germanium were Purdue — Lark Horovitz — and Bell Labs.
Of course there was a good deal going at the Radiation Laboratory. Hill Huntington was there.
And what did he do?
Well, he had joined the laboratory and eventually ended up working with a group that was interested in such things. They also acted as coordinators with various contracts. As we said yesterday, he would be well worth interviewing. He lives in upstate New York. He was at Rensselaer Polytechnic. He's retired but still keeps an office there, in Troy, New York.
That's not so far away. To get the major contributions of the war on semiconductor physics I'll have to study the reports that were produced.
Yes. I don't know to what extent they're available. We used to have — I guess they were bimonthly — meetings of all the people that were interested, many of them from industry. There was a group at General Electric, group at Westinghouse, the Lark—Horovitz group, Bell Labs, and then, some hangers—on who would come to those meetings.
Where did you meet?
We met around. I know we had a number of meetings at Columbia because it was convenient.
How often were the meetings?
About once every two months. People would review their research.
I see. It would be very interesting to get outlines of the meetings, programs, whatever.
Somewhere on my shelves I have a copy of the report that the Radiation Lab wrote. I can give it to you after we're finished here, if I can lay my hands on it.
That would be very useful.
There was a Radiation Lab series that was edited by Louis Ridenour.
Yes, that's available everywhere. You're referring probably to Tovvey and Whitmer.
I've used that.
Well, you know it then. That has about as thoroughgoing an account of the things that went on, but it may not mention the seminars. As far as I know, they went on almost to the end of the war. But I lost contact with them from about 1944 on, because I got involved in other work and also with the Met Lab in Chicago.
During the war you did more work on dislocations. For example, there's a paper on interpretation of creep in terms of dislocations. Now, was that a direct outgrowth of the war work?
No, just of interest. Jimmy Koehler was working with me, and we kept conversations going, worried about these things.
I see. You say — this must have been a talk that you gave at the APS in ‘41 — “examination of the meager available creep data indicates” the need for more thinking about the problem, basically, and you suggest a model.
There were books on empirical studies of creep in metals, done often on practical specimens.
I have a general question about imperfections, and that is why they began to be studied relatively late. Because one can understand why the electronic structure wasn't studied earlier; you needed quantum physics for that.
But here most of the models are classical. Why?
Well, one needed to be sure of the base. There was a man in Germany named Smekal who wrote voluminously on the subject of imperfections in metals. It was always on a very quasi—mystical basis.
Smekal's work must have been in the twenties?
In the twenties, yes. I met him either late in the war in Germany or in the United States. He was a voluminous writer.
Why was it on a mystical level?
Because one didn't really know what was going on. It took more people doing more experiments. And then one needed to work at the range where one had almost perfect crystals.
Well, that's something that was not available, until later, and that could explain it.
That was a big factor.
But the theory, it seems to me, should have been done very early in the century, or even in the last century, some of it.
Well, you know, there were things like Karl Wagner's work on ionic conductivity, and there one had very explicit models. That was good work. He worked in the thirties, electrolytic conductivity in various materials. There were people connected with him but he was the most outstanding one. He was at a laboratory at Darmstadt. Eventually he came to the United States, I think spent time either at M.I.T. or at Chicago, but finally went back to Europe. This all happened after the war.
I've come across him. But again that was work that was done in the thirties.
In the thirties.
And by then one had a framework.
By chemists who were quite good and precise. Then there was the experimental work at Gottingen, which often didn't relate too much to atomic models, but was good. They worked with low levels of F centers and things of this kind. But you're right that it didn't pick up until a number of people began to make nearly perfect crystals in systematic studies.
There were certain ideas that built upon the quantum physics basis, such as anything that had to do with holes for example.
Yes, that's right.
But one could probably have had something like that idea, without the basis for the whole they earlier.
There's not much to say about the EFFECTS OF ALLOYING ON ARCHITECTURE. This was obviously a tack we'll go on. We should talk about your move to the University of Pennsylvania, Morgan Lab.
Morgan Lab, yes. I left General Electric Lab. There had been a steep recession, referred to at the time as the Roosevelt Depression, after a period when things had begun to pick up. I think it was the fall of 1938, things went to pieces in a hurry, and at that time Hernwell asked if I'd join him at Penn. Since Philadelphia was in a way our old stamping ground, we went there. Very interesting time. Then he left temporarily during the war to head a submarine warfare laboratory in San Diego, and I was offered a job at what's now Carnegie—Mellon, at Carnegie Tech, and left, I guess, at the end of 1942. And Maurer came with me.
While you were at Carnegie Tech you worked with Thomas Read in Pittsburgh.
That work had started a little earlier with a series of papers.
This is the series of papers, one of the outgrowths of it was —
We began to get some glimmerings of the importance of dislocations, from many things, and in that primitive way, tied this all together.
Was Thornton Read available?
No, this was Tom Read. Thornton Read I think was at the Bell Labs. They're quite different people. Thornton worked with Shockley. Tom was at Westinghouse when I first met him. Then I told Herschel Smith about him, and he moved to Frankford Arsenal, spent the war years there. Then he got a job at Columbia, metallurgy department, and then was offered the job as head of the metallurgy department at Illinois, and died there about 15 years ago. 12 years ago.
Is that the position that Nurer then got?
No, that was over in metallurgy. Maurer's position, which I guess he left a year or so ago, was a result of a creation of an interdisciplinary laboratory early in the 1960's, which I was able to pull together with federal help. Tom was still head of metallurgy and was part of the governing board.
Tell me about these articles, how they happened to have been written and what need they were supposed to fulfill. They're a comprehensive presentation of the subject of plastic flow and some of the history.
That's right. We tried to pull together all the things that seemed to be reliably known and interpret them as well as one could, in terms of the rather primitive theory we had then. We didn't understand then how dislocations could multiply themselves. These things came to light after the war, when the Bristol group and others got going.
I did notice there were some references to the twenties.
There was some good work done.
Becker, Smakula, Griffith.
That's right. Griffith's work was very early, on the strength of glasses.
This is one of the areas where the strength of materials side comes in. I've been impressed with some of Cyril Smith's papers on history of metallurgy and solid state physics, in which one of his big points is that there were really two different traditions for a long time, a craftsman's tradition — craftsmen and artists' tradition — and a scientific tradition which began very much later. And these stayed almost entirely separate from each other, because people had a different point of view.
And this is one area where the two traditions seem to be coming together.
In the twenties.
The traditionalists, what you've referred to as the craftsmen, were so to speak stuck with the field. They had to stay in it. The others could move in and out, more or less for the intellectual impact. If they had an idea they worked on it. If they didn't they'd work on something else.
Another big distinction also is that the physicists, the ones who moved in and out —
— and chemists —
And the chemists. Their point of view was to generalize and to see things in terms of ideal models, whereas the others were stuck with the materials, with the specifics, with the full complexity of the difficulties with some specific object that they were trying to make strong.
Another exciting thing occurred. When people first began making single crystals of pure metals, like zinc, or whatever, they were amazed at how soft they were, This was quite a challenge.
When was that?
That was in the twenties. There were a series of techniques developed then, like the Kyropoulos and Czochralski methods of growing crystals.
Where were these developed?
They were developed mainly in Central Europe, although G.I. Taylor got involved later on in his work on mechanical properties of single crystals. There's a book, either Taylor and Elam or Elam along summarizing all that. Undoubtedly referred to in here somewhere. Bridgman also developed a method of growing single crystals.
It probably is. There's a Taylor, 1934. Koehler stayed on this for many years.
Yes, he stayed for many years. Re remained in Urbana.
He's still in Urbana.
Yes. Re was taken on — what were the circumstances? Re was at Pittsburgh. He came to Pittsburgh and joined the faculty from Westinghouse, where he'd been one of Condon's fellows, and stayed there until about 1950, and then joined us in Urbana. And stayed. During the war he did some very fine work on self—diffusion in uranium and worked on dislocation theory. Re took to it in a big way and has remained. Got interested in radiation—induced defects along the way. He's probably more of a recluse now than he was in the early days, but he's had a long history. He worked with some very good people at the University of Michigan too.
Who did he work with?
Well, he knew Otto LaPorte well also Uhlenbeck and Randall and such people. Otto LaPorte was a theoretical physicist who studied with Sommerfeld, came to the United States. Dennison was another person he worked with, David Dennison. People involved in molecular spectra.
I'll have to question him on all that. It's interesting, in your life you picked up many threads in different places and then continued them.
Well, you know, one was groping to try to get clear understanding of all these things and at the same time to make it useful.
It was only later — and we'll come to that in the fifties — that you tried to put everything together to form a synthesis.
We were beginning to get much more general understanding of imperfections in 1950.
Now, is there anything to say on the Conference on the Hardening of Metals? I know Shockley spoke at it. I don't recognize the other name.
No, I think this was just the boys getting together.
This is during the war.
I see Sid Siegal was working on precipitation and hardening at that time. I tried to get him to come to Urbana, but he got interested in reactor physics and went out to the West Coast to work at one of the laboratories there on high energy reactors. Sodium graphite.
The work with Hill Huntington on self—diffusion in metallic copper — we started talking about that a little bit yesterday. Was this a wartime project or was this done before the war?
That was done in the main before the war. I don't know whether that was Hill's thesis or not. It may be that it was done in conjunction with whatever his thesis was. I think it perhaps was his thesis at Princeton.
I see. This is a paper which indicates that the vacancy mechanism is the preferred one.
We used all the tools to see whether it was interstitial diffusion or self diffusion or jumping and he examined all the barriers, and it has since turned out to be pretty good.
It seems to be very well put together.
Hill has been a very steadfast, creative person and would be well worth interviewing. He also lived with the group in the Radiation Lab.
I will contact him. The darkening of materials by light — this is something that you probably started in connection with DuPont?
No, I started that at GE, but the paper wasn't published until I'd gone to Penn. It was that paper that got the Dupont people interested in having me work with them. I didn't realize it was published that late. Usually one was so busy that one let things hang around. I did some work on sulfide, zinc sulfide. That was the GE work.
You did more work on this in Pittsburgh.
It was one of those things I kept going. Another thing I should say is that after I went to Pittsburgh, I went up to the Radiation Lab to see if there were things we could do there, because we'd left all the silicon work back at Penn, and they were interested in developing what in the U.S. were called dark trace tubes; I guess in England were called the skiatron.
Right. Now, what is this skiatron.
You have a layer of alkaili halide, and you bombard it with electrons and produce F centers. One wanted it to be visible in ordinary light.
You bombarded with?
Cathode ray tubes, electrons.
And it'll darken. And the whole trick was to learn not only how to darken, which was easy enough if you have a strong enough beam, but also to bleach. So we had quite a program going at Carnegie Mellon, that went essentially through most of the war, on dark trace tubes.
Some of the people who worked on it were Estermann, Stern, and Maurer?
That's right. Otto Stern, who was famous for the Stern—Gerlach experiment, went to Carnegie Mellon, in 1934 I believe, and picked up his work on molecular beams. Estermann came with him. And when I arrived in ‘42, they were very anxious to get into some kind of war research and got involved in this. Later on I got Stern made a consultant to the Met Lab. He and Franck were old friends. It was a lot of fun. On a Sunday morning I'd often go around to see Stern. He'd been a very vivacious person in Europe, but America was just too much for him. He came here too late. You know, experiences in the Depression weren't pleasant. Things had been so much better organized for him in Europe. He was head of an institute, had all these civil servants, pretty ready access to government funds, even though there was also a Depression in Europe.
How old was he then?
Well, let's see. He died early in the decade at the age of 80, and that would have meant he was born about 1880. Maybe a little later. He was a young officer in World War I, so he was born sometime in the 1880's, maybe nearer 1890.
So he was not that old at the time.
Well, I always thought there was a break point at age 35. People who came here under 35 managed. He was probably in his forties when he arrived in Pittsburgh. Getting money was hard, and he didn't have the talent for raising money in the United States. But he carried on. He had work he managed to do.
Did he stay in this area or did he switch around?
No. He got the Nobel Prize along with Rabi. He got one of the wartime prizes which had been held in abeyance by the Swedes. I think Rabi got the ‘45, Stern got the ‘44, or maybe ‘45, ‘46. In any case, he got a Nobel Award, and then he decided on the basis of that — he got the entire award — to retire, and went out to California, bought a little house in Berkeley. He had a close friendship with G.N. Lewis at Berkeley, although Lewis died somewhat prematurely. I used to visit him at Berkeley occasionally. He was a rather lonesome person, but he had a very interesting early history. He spent a couple of years with Einstein at Prague, and those were the great days of his life. They had a wonderful time together. He used to love to talk about that. He remained close to Einstein. They would meet frequently and discuss physics. He spent the last years of his life working on a concept that I don't think got anywhere. He felt intuitively that there must be a relationship between Planck's Constant and the Boltzmann Constant, and he worked in that area.
What about Estermann?
Estermann had been Stern's assistant. He was a good physical chemist. I think he had worked with a physical chemist named Vollmer in Berlin and then got a job as top man next to Stern at Hamburg and came to the United States with him. He was quite flexible. He stayed at Carnegie Tech until about 1950, continuing work of this general kind. Then he took a job with the Navy, actually spent some years in the London office of ONR. I saw him in London a number of times. And then he decided to go to Israel, spent his last years there. He was a very meticulous and precise experimenter.
Now, this work on F centers under electron bombardment was later improved on a lot by Heinz Pick and his group?
Yes. As instrumentation developed in the postwar period, a lot of things were rehashed.
What instrumentation in particular was required for this work?
Well, you see, this was wartime work. We were trying to understand the properties of the evaporated layers, while we did a little work on single crystals, it was secondary, because you had a practical problem by the tail, by the horns. And in the postwar period, people went back to growing single crystals, working at the ideal limit where everything was clean and so forth. So they could do much more careful work. Pick and I got into an argument about the model for one of the centers. I guess it was the M center. He turned out to be right, and I think he's been very pleased with that. But we were good friends. We had Pick visit Illinois for several months, 1951 or so. That was when he was still at Gottingen and before he got his job at Stuttgart, where he became a very important leader.
Is there anything else we need to say before we move to Chicago?
No. I think you've got most of it.
In 1943 Arthur Compton asked you to come to Chicago.
Well, that's the formal statement. Actually, what happened is that Eugene had been working on reactor designs for about a year. He believed that the simplest and most direct way to make plutonium was with a water cooled reactor, and he, Alvin Weinberg and Gale Young designed such a reactor, in very great detail. There were other people who thought that the right route was by a gas—cooled reactor, helium—cooled reactor. There was about a year spent in which Wigner and his little group were developing in great depth the properties of this hypothetical graphite reactor. The other group ran into a stone wall and quickly came back, and the decision was made to go ahead with graphite reactors. At that point Eugene had realized that there were going to be some material problems.
So while technically he had Arthur Compton invite me to come, what actually happened is, he asked if I'd visit Chicago. Matter of fact, Johnny Bardeen and I were there at the same time. It may not have been my first visit, but I know we met there, because Eugene also tried to get John to join the Met Lab. But he was working on torpedoes in Washington at one of the naval ordnance labs, had his family well established there, and didn't want to go to Chicago. I was more footloose and also intrigued, so some time in ‘43, I moved to Chicago. Betty actually was teaching at what was then called the Pennsylvania College for Women in Pittsburgh as her wartime contribution, and she stayed.
What was she teaching?
Physics and math. She had a reasonably heavy load.
So you were separated during this period.
Well, I'd commute. Chicago wasn't that far, though I certainly got tired of riding the trains. It was an overnight train trip, between Chicago and Pittsburgh. I'd come home about once in two weeks, and occasionally Betty would come to Chicago and enjoy that fine winter weather. I spent two years working. Also kept a few other things going. I kept a link with DuPont on their materials program and one foot in the silicon program. I would also come back to Pittsburgh to keep the department running, although I had a lot of good help. We had started another program in Pittsburgh on defense against something called shaped charges. It was a so—called hollow charge weapon, which is properly known as the bazooka. There was a laboratory at Bruceton, Pennsylvania, which was under the charge of George Kistiakowsky.
That was an explosives lab.
Explosive lab, yes. In contract with Carnegie Tech, just for bookkeeping. And they wanted some group to work on the defensive side against these weapons. We started a program in Pittsburgh, when I was still there before going to Chicago, and that was headed by Professor Emerson Pugh, who has recently written an autobiography about various aspects of history. He was at Cal Tech in the twenties and came to Carnegie, and then was put in charge of this program, and ran it after I went to Chicago. I used to come back and see what they were doing and what the dark trace tube people were doing. But most of the time was spent in Chicago. A very exciting period.
Tell me more about that Chicago work. There must be some unclassified reports on it.
The question is where?
Where, yes. I don't know what ever happened to the records of the lab. We had to write monthly reports and all that,
Maybe they're just at Chicago. They may be at the University.
Well, Eugene got concerned, said, “We'll probably have materials problems.” He did a few estimates of work for things on graphite which concerned him most. We talked a little about this when you interviewed him. He got James Franck interested in it and then Milton Burton, who set up a laboratory which had a group of young chemists to work on it. I decided I would join them, and then I was put in charge of the theoretical side of this. We did as exhaustive as we could a study of all the various constituents. I came to the conclusion that while the graphite problems were serious, the real problems were going to be with uranium itself, which had all the fission products in it. We did a pretty good job.
It had to be only semi—quantitative because, again, you were extrapolating from very small amounts of experimental data. Incidentally Maurer came and joined the lab, did some very nice experiments on energy release from graphite that had been irradiated. But with all the cyclotron radiation we could muster, the radiation equivalent was about one day of Hanford Operation, and of course those reactors were supposed to operate for several years. So we were taking long extrapolations of things that we were sure about on the basis of meager data. But, in general, we got a pretty good grip on the problem. Interestingly enough, the construction people didn't want to hear about it, although they eventually had to face all these troubles.
They just didn't want to be bothered, or were there other reasons?
Well, they had too much else to do. Everyone was very busy, you know, and “Don't bother me with that, can't you see I'm busy?” We tried to get them to put a lot of test equipment in the reactors, but they were afraid it would spoil the continuity of the manufacturing process. Fortunately, everything worked in spite of the fact that these predictions weren't taken very seriously. There was enough latitude in the shape of the structure that one went for several years. The English, however, got in serious trouble with their reactors. Our work was completely classified. They built graphite reactors, and, as Eugene said, some of them got so much stored energy that it let loose and they had a serious problem on their hands. That was in the postwar period. They got going seriously on a quantitative scale after the war when they were developing power reactors.
Do you know if this work is still classified?
That I don't know. I wouldn't think so. But I know it was in the early fifties, because the English sent over a team to explain their problems, and the AEC gathered those of us who'd worked on it together, and we tried to talk in code, you know, saying “Gee, that's interesting, but maybe one could do this,” Of course we knew these were just the things we had recommended, namely baking out the graphite at various stages, letting it overheat so you'd get rid of the stored energy before it was hazardous.
Were you asked to do any work that pertained to the building of the bomb at Los Alamos?
No. They built a rigid wall, although there were leaks back and forth, as there inevitably would be with scientists. Arthur Compton knew everything. He was in the inner circle. I was in Europe by the time the Trinity test went. I was asked if I'd join an intelligence office that was set up, first in Paris, Versailles, then later on we moved to Frankfurt after V—E day, so by the time of the July test I was gone.
While we're on war things, did you have anything to do with the start of the work on neutron diffraction?
Yes. Fermi got excited once they had their one megawatt reactor. Zinn was in charge of that -— Wally Zinn, Walter Zinn, He had been an expert on X—ray diffraction in the thirties, had worked, I think, at City College. He's one of those people who did research at Columbia. Fermi did a few rather basic experiments on diffraction, very beautiful things with very simple equipment, which was Fermi's marvelous gift. Then Zinn picked this up and I worked with him on the theoretical side. There's a paper, I think it was published by Murph Goldberger and me.
Oh yes, I have the paper here. 
There's a manuscript somewhere too. It appeared in the PHYSICAL REVIEW. Willie Zachariasen had written a book, the best book, I think, on the theory of X—ray diffraction. All of this was readily translatable over to neutron diffraction, I wrote a big manuscript on the neutron counterpart. Then eventually Murph and I worked it over and published it. He had been a student at Carnegie, class of ‘42, worked a bit with us as a kind of assistant on the dark trace business, then got drafted. I had the Manhattan District fish him out and brought him to Chicago, where he became a part of the theoretical team. As a matter of fact his wife, Mildred, was a computer expert by the standards of the day, and that's where they met.
How did you happen to notice the effect on the transfer?
The interaction with lattice vibrations was very important, much more so than with X—rays because of the mass of the neutron. In the course of it, I noted that there were instances in which you could get diffraction without transfer. This was the effect which later on became very, very important — the work of the German physicist, M8ssbauer. I remember that when the M8ssbauer paper appeared, someone came into my office at Urbana and said, “Say, does this stuff make any sense?” And of course it all came together and all I could say was “Damn it, I missed it.”
You were very close. Meanwhile, the work on semiconductors was continuing at Penn.
Yes. I saw the group occasionally; once in a while when I was in the East I'd go to one of their meetings, those bimonthly meetings I mentioned.
This paper on the basic principles of semiconductors was, I gather, written long before it was published. It was published in October 1945.
That's right. This was probably one of those things that one could write after. Let's see if there's any work at all on the — I wonder if we were still under constraint. I was still talking about zinc oxide, cuprous oxide. We were still under constraint on silicon, I think. I don't think there's any mention of it here. Because we knew a good deal about it. The work on lead chromate is mentioned. That was the work that DuPont sponsored. One of the people at Westinghouse who continued to work on semiconductors — I don't know what he's doing now; let's see if he's mentioned here — did work on copper oxide. Angelo, Steven Angelo. He's still at Westinghouse. He joined that team I mentioned.
There are a couple of papers, general papers you wrote: “Whither American Physics?” was just a symposium talk, and “The Relationship between Energy and Mass.”
That's probably just a popular talk.
Where did that appear?
Oh yes. I think that I was at Carnegie—Mellon and was asked to give a talk and someone wrote it up.
I see. There are just two more pieces of work that I think need to be discussed before we move to Urbana, and that might be a place to break. One is the big REVIEW article on color centers in alkali halide crystals, which was an enormous piece of work. And this is a talk on the same subject? How did this come to be written?
Well, it was inspired by the wartime work on the dark trace tubes, and of course I spent a lot of time just stewing over things. What is the date?
For the most part it was based on summary that I wrote for wartime use.
It's based in part on the bombardment by cathode rays of the alkali halides.
This is a time when this subject seems to have come into its own for the first time.
That's right. Well, Nott had done some work. You know that book of his.
Nott and Gurney?
Nott and Gurney, “The Theory of Almost Perfect Crystals,” or “Nearly Perfect Crystals.”
Ionic processes, yes. The nearly perfect crystal business came up postwar, but it was a book that appeared about 1940. There's a good deal in there, of models, We tried to push it farther, During the war we recognized that there were things going on at room temperature that we hadn't supposed, and there is an attempt here to unravel that. Because we discovered there was bleaching of color centers at room temperature.
Was this supported by industry at all, or was this just a straight academic subject?
A straight academic thing. Probably the biggest effect we had was that it got the people like Pick interested again in these things.
Had he stopped being interested?
Yes. He had a rather rough time during the war. He never joined the party or anything like that, and young people who didn't found it hard to get a decent job. I forget where he spent the war years. Doing something, I think, in industry. And then Pohl took him on again for a period. He was the second man at G8ttingen. Partly because of the interest that Nott and the English group had in these things and our own, they really got back to work on color centers, and more a part of the international discussion.
Where were the major centers for color centers? Bristol and Goettingen.
Yes. The Gttingen people did the best experimental work in that period.
Was that mainly due to Pohl's influence?
Pohl's influence, yes. There were other things done but the work that his group did was usually very accurate, highly trustworthy, and done with considerable intuition, an intuitive sense of what was right. There wasn't a great deal of experimental work done at Bristol. It was mainly a theoretical center. Then things began to start in the United States. Our group at Illinois with Maurer and so forth. And then it spread from there, and the silver halide research also stimulated interest.
Would you say the Illinois group was the major group in the U.S. for a while?
For a while, yes.
That started after ‘49, after you got there.
Yes. You know, then electron and nuclear resonance techniques came in, and people all over the country began to study color centers. They were good things to study. There was sort of an explosion that started around 1950.
I noticed that there are some references to papers in the thirties by Landau and Bohr, for example, in this paper.
There certainly were roots.
Oh yes. A good deal of the best G8ttingen work was done in the thirties. Pohl was an interesting man. He apparently died a couple of years ago. He has a son who is at Cornell, Robert Jr., I guess. He began working on things which were very close to those of industrial interests in the early twenties, particularly working with a man named Gudden who went into industry. But then as the decade moved on, he got involved in more refined types of experiments, as we would say now with nearly perfect crystals. He had a fine school of young students working with him in the thirties.
I gather he shied away from theory somewhat. He only trusted the experiments.
Well, yes. He, I think, was overwhelmed by the brilliant theorists at Goettingen, and said he'd go off and do his own thing.
Did you know him?
Oh yes. I visited Goettingen in ‘45, when I was on this intelligence work, and I saw him briefly then. The most exciting thing was, I saw both Richard Becker and Planck. There was a fellow Mallwo who was his chief assistant at that time, someone who incidentally was well known to Foster Nix. They were excluded from their own laboratory.
Well, it was part of the Occupation, afraid they'd make a bomb in the basement, They had, I don't know, 1000 volts of wet cells that were going to deteriorate, and they came to me when they heard I was in town —- the grapevine worked very fast — and asked if I would help them get in so they could put distilled water in the batteries. So I arranged that. Those are odd periods. You have to live through them to appreciate what it was like. I went to G8ttingen with Sam Goudsmit and Bob Robertson. Then I saw him again in 1949.
Were they part of the Alsos mission?
Well, the Alsos people had a set of offices in our complex in Frankfurt. We had a group of offices, and Sam and General Pash, liked to come there and use it as a headquarters.
Then it was either ‘49 or ‘51, I think it was ‘49, G8ttingen had a symposium to which they invited a number of people, Mott of course, one or two of his people, and Bob Naurer and I went, It was quite a gathering. Schottky was there too. He'd just been a name on top of a very complicated series of papers. He turned out to be a delightful man.
Were his papers read carefully by people here? They're so long and so complicated.
If anything could be done simply, he would do it in a complicated way. Yes, one read them. They tended to be very obscure, He was very thorough, a gentleman of the old school.
I gather he came across lots of things that were later rediscovered.
They were just obscure in his papers.
I suspect if you lived with him you would really know what he was doing, but when it came to writing papers he wanted to leave no stone unturned, so they got complicated. That was one of Nott's great gifts,that he could cut through the stuff, gaining clarity at the cost of precision if that was what was needed.
I'm sure the British are going to interview Mott very thoroughly.
I have lots of questions about that Nott—Schottky theory myself, Just one simple one, Maybe you just happen to know the answer, It just has to do with the relationship between the two, Was Nott familiar with the Schottky papers at the time?
He must have known of their existence, because they were in the standard literature.
To what extent was Mott's contribution original? Certainly people read the Mott papers. They couldn't understand the Schottky papers.
I know Dushman used to say, “The guy who sells it deserves at least half the credit.”
I'm not giving Mott enough credit, perhaps?
No, Mott was certainly a highly original thinker, And it's quite possible that he discovered these things in one form on his own, and then in going through Schottky's paper, recognized that Schottky had done it too. Mott was producing things at a sufficient rate that priorities weren't very much of an issue.
One of the things that I found very peculiar at the time I was looking at this — and not very thoroughly, I need to go back and do it better — this was just in connection with getting some background for the transistor studies I did — was that the Wilson theory which had come out a long time ago, in ‘31, hadn't been replaced until the Nott— schottky theory came out in ‘38, ‘39. It predicted the rectification to be in the wrong direction.
The Wilson theory?
Yes. And even Wilson pointed that out in his book written a few years later. I think his book came out just at the time the Mott— Schottky theory appeared, and he hadn't yet digested it but said, “There's this new theory which looks like it might solve the problem” But weren't people bothered by that? Seven years to get the rectification in the wrong direction?
Well, there weren't many people working in the field, I knew of Wilson's book, but most of the things in it were things I already had learned from reading the original literature It was a typical Cambridge tract which proceeded in a sufficiently formal way that it didn't sink in to me the way it should have, It's the same problem that you're describing on a different front.
There's just one paper, here, still in the forties — I don't know if you have anything special to say about it — on the theory of electron multiplication in crystals —
I got interested in breakdown.
Yes, it's related to Zener breakdown.
Well, there are two kinds, There's Zener breakdown, in which the field is strong enough that you pull electrons across the band gap. Something which Clarence had done, I guess in the mid—thirties, And what I discussed was the avalanche breakdown that is essentially what you get from gaseous discharges. While the ideas were original with me, it has been pointed out that they are close enough to what people have done on gases that it's not a remarkable piece of paper, although I was able to correlate some experiments that were otherwise unexplained.
It's a good paper. And this was certainly an outgrowth of your war work? or not?
No, I think I found some experimental data that was intriguing. Yes, there's this work of Hayworth and Bozorth. Also von Hippel did some work, I think that was the Bozorth at the Bell Labs.
Franz did some work in the pre—war period. Yes, R.N. Bozorth, 1934. Just one of those things. You know, you just have a paper and you read it and wonder what it's about and then start working.
Actually there are a couple of little questions I have left, but I can ask you those at the beginning next time. We covered all the papers that I wanted to discuss from the forties, We can start next time and work on the fifties papers. I have a few little questions about Pugwash and so on.
That's still in the forties. I think you did a great job.
One thing we might talk about too is, I spent a year, '46 – '47 at Oak Ridge, running that school. Again, Eugene asked me to,
Where you worked on ballistics, radar, and nuclear reactions.
No, we ran what was called the reactor school, had 35 people. Eugene was anxious to push the peaceful uses of nuclear reactors and moved to Oak Ridge. He asked if I would run his school, so I was dean of what came to be known as the Clinch College of Nuclear Knowledge 1946–47. We got 35 applicants from various places, industry and so forth and went through a course of fundamentals on nuclear reactors, gave a series of lectures on radiation damage. Very interesting year. As a matter of fact, Eugene laid the groundwork for a large amount of reactor technology, He saw well into the future.
What other points did he look or worry about that led to groups of people working on the subject in reactor technology?
I suppose these things have all been declassified, but a literature was built up at Oak Ridge on reactor design of various kinds. He stayed about two years, as I recall. I came back at the end of the year.
I'll have to get in touch with the people who are in charge of papers at Oak Ridge and the Met Lab and see whether or not there are some ways of exchanging material. Well, thank you. Have a great trip.
I don't know if O.C. Simpson is still at all in evidence at Argonne. He was director of solid state research, Retired three or four years ago. I don't know whether he's retained any contact.
Is he someone to interview?
He might well be. He ran that solid state laboratory. He had people like Delbecq and Yuster. I don't know if they're still there. Do those names mean anything to you at Argonne?
No. If you'd give me just a little bit of background?
Well, he pulled together a laboratory that had some very good people in it. Let's see if Delbecq still exists. (Looks in directory.) Yes, Delbecq is in Building 223 of Argonne National Laboratory.
I can drive over there very easily.
Charles J. Delbecq. You might ask him, He was a very good man, did color center work, He worked with a fellow named Yuster. I think you ought to meet them, Yes, Yuster is there too, although it gives his home address — Phil Yuster, Downers Grove.
Many, many thanks, and I'll be in touch in a month or two as soon as I know my schedule.
A, Sommerfeld and H. Bethe, HANDBUCH DER PHYSIK, XXIV/2 (1934).
See my interview with Bethe on 29 April 1981 for further detail about this article. L.H.
See recorded comments of advisory meeting, International Project on the History of Solid State Physics, February 1981.
THE PHYSICS OF METALS (McGraw-Hill, 1943).
(The seventh impression at least is on excellent paper! L.H.)
CRYSTAL RECTIFIERS, 15, M.I.T. Rad. Lab. Series (New York: McGraw-Hill, 1948).
“Effects of Alloying on Architecture,” Frederick Seitz, pp. 11–24 in METAL — INSIDE OUT, 1941 (Cleveland, Ohio: American Society of Metals).
“Conference on the Hardening of Metals,”Frederick Seitz, JOURNAL OF APPLIED PHYSICS, 13, pp. 74–89 (1942).
“The Darkening of Materials by Light,” Frederick Seitz, JOURNAL OF APPLIED PHYSICS, 13, pp. 639–43 (1942).
“Refraction and Diffraction of Neutrons by Crystals,” N.L. Goldberger and Frederick Seitz, PHYSICAL REVIEW, 70, p. 116 (1946).
“The Basic Principles of Semi-Conductors,” JOURNAL OF APPLIED PHYSICS, 16, pp. 553–563, (1945).
“Color Centers in Alkali Halide Crystals,” REVIEWS OF MODERN PHYSICS, 18, pp. 384–408 (1946).
Present Aspects of the Theory of Color Centers in the Alkali-Halides, F. Seitz, PHYSICAL REVIEW, 68, p. 283 (1945).
N.F. Mott and R.W. Gurney, ELECTRONIC PROCESSES IN IONIC CRYSTALS, 1940.
“On the Theory of Electron Multiplication in Crystals,” Frederick Seitz, PHYSICAL REVIEW, 76, pp. 1376–1393, (1949).