Electrical and structural properties of YHx (x∼ 3) under high pressure.

The electrical and structural properties of yttrium hydride YHx (x ∼ 3) were studied by the in situ measurements of the electrical resistance and X-ray diffraction up to 86 GPa. The electrical resistivity ρ increased with applying pressure up to 10 GPa and showed a maximum, which was accompanied with the structural transition of metal lattice from hcp into fcc structure. In fcc phase the ρ decreased significantly, however, the value was still high as 75×10-2 (Ω cm), which is larger by four orders of magnitude than that of pure yttrium metal. We could not confirm the insulator to metal transition up to 85 GPa. The ρ showed another maximum in the large pressure region 40-60 GPa without the structural phase transition of the metal lattice. [ABSTRACT FROM AUTHOR]