We investigate the electron transport properties and structures of β-NbH x (010) epitaxial thin films on Al 2 O 3 (001) substrates with a variety of hydrogen contents. NbH x epitaxial thin films with x ≥ 0.77 exhibit a hysteresis loop in their resistance near room temperature. Notably, this hysteresis loop appears above the β-λ phase transition temperature. Detailed analysis of the temperature dependence of these structures suggests that the short-range ordering of hydrogen rearrangement in the λ-phase remains locally above the transition temperature, inducing the hysteresis in the resistance.
ASJC Scopus subject areas