Iron Superconductivity.

The highest superconductivity transition temperature for a non-copper material has been achieved: 44 K by Japanese scientists at the Nihon University, the Frontier Research Center, and the Tokyo Institute of Technology and 55 K at the Institute of Physics in Beijing. To attain a comparatively high transition temperature, the Japanese researchers had to squeeze their La-O-F-Fe-As sample with a pressure of 4 giga-pascals. (Takahashi et al., Nature, 23 April 2008) Even higher transition temperatures (55 K) in arsenic-iron compounds are reported to have been made in China (see Science, 25 April 2008).