Using neutron Bragg-edge spectroscopy to analyze complex magnetic materials

Over the past few decades, advanced magnetic materials exhibiting intricate magnetic textures have been adopted in practical applications such as energy and digital storage. Their complex internal magnetic structures are challenging to study using existing techniques. Neutron scattering offers a means to probe these structures, but conventional approaches, like neutron diffractometry, lack the throughput required to rapidly analyze materials and the ability to image complex internal magnetic state distributions.

Mamiya et al. explored how Bragg-edge spectroscopy can be used for high-throughput characterization and in situ imaging of complex internal magnetic structures in advanced magnetic materials.

In contrast to conventional diffractometry, which measures scattered neutrons directly, Bragg-edge spectroscopy measures the decrease in neutron transmission caused by the scattering. This technique not only allows for internal visualization of materials but also for high throughput due to multi-sample imaging.

“Bragg-edge imaging provides non-destructive mapping of internal magnetic state distributions in bulk materials, making it effective for quality control and evaluation of magnetic devices after assembly and during operation,” said author Hiroaki Mamiya.

The team demonstrated the effectiveness of the technique by testing it experimentally on samples of magnetic materials including holmium and high-carbon steel, successfully observing a temperature-dependent change in magnetic structure in holmium and polarization dependence in steel.

“Future plans involve applying this method to a broader range of magnetic materials and devices, contributing to their development while using the results to further refine the methodology,” said Mamiya. “The knowledge gained will support the broader adoption of these techniques for developing and evaluating practical magnetic materials and devices.”

Source: “Role of neutron bragg edge spectroscopy in development of practical magnetic materials,” by Hiroaki Mamiya, Noriki Terada, Kosuke Hiroi, Takenao Shinohara, and Hossein Sepehri-Amin, Journal of Applied Physics (2025). The article can be accessed at https://doi.org/10.1063/5.0285904 .