Electrical resistance measurement techniques for metal hydrides under high-pressure H conditions & electrical transport and structural properties of FeH

Matsuoka, Takehiro*; Hirao, Naohisa*; Oishi, Yasuo*; Shimizu, Katsuya*; Machida, Akihiko; Aoki, Katsutoshi

We present the newly developed electrical resistance measurement technique for metal hydrides compressed in high-pressure H and the first successful simultaneous measurements of electrical resistance and X-ray diffraction of FeH at high pressures and low temperatures. The electrical resistivity showed a sharp increase with the formation of iron-hydride FeH () at 3.5 GPa. The '-phase of FeH was found to be metallic up to 25.5 GPa. The vs. curves up to 16.5 GPa approximately follow Fermi-liquid law below 25 K. However, was found to be better fitting at 25.5 GPa. This change can be related to the previously reported ferromagnetism collapse at corresponding pressures.