Resistivity study of β-${\mathrm{TbH}}_{1.93+\mathrm{x}}$: Observation of an anomaly near 150 K similar to that found in α-R${\mathrm{H}}_{\mathrm{x}}$ solid solutions

The electrical resistivity of β-${\mathrm{TbH}}_{1.93+\mathrm{x}}$ is shown to exhibit an anomaly near 150 K whose amplitude increases with increasing x. A quenched-in Δ${\rho }_q$ recovers in the anomaly region. The phenomenon is very similar to the 160-K anomaly in some α-R${\mathrm{H}}_{\mathrm{x}}$ systems and is attributed to short-range ordering of H-atoms on octahedral sites or to localized precipitation of nuclei of the H-rich phase.