Logarithmic Divergence of the Electrical Resistivity in the Metal HydrideYH3−δ

As reported earlier, the metal hydride ${\mathrm{YH}}_x$ reveals spectacular switchable optical properties. In this Letter we report on another remarkable property of the hydrogen deficient ${\mathrm{YH}}_{3-\delta }$ trihydride phase. A logarithmic temperature dependence of the electrical resistivity is observed within a large temperature range $\left(20\le T\le 200\mathrm{K}\right)$ for hydrogen deficiencies $0.01<\mathrm{}\delta <0.15\mathrm{}$. This dependence may be related to two dimensional weak localization or Kondo scattering of the conduction electrons.