Features in the temperature dependence of the resistivity and the critical parameters of the superconducting state in H/sub x/NbSe/sub 2/

The temperature dependence of the resistivity and angular dependence of the magnitude of the second critical field H/sub c/2 in single crystals of the layered superconductor NbSe/sub 2/, intercalated with hydrogen, was investigated experimentally. At hydrogen concentrations of 0.13, 0.66, and 1.0 at.%, the temperature dependence of the resistivity exhibits features that are apparently related to the formation of hydrogen-containing clusters in the NbSe/sub 2/ matrix. Modulation caused by the formation of a superlattice of hydrogen-containing clusters was observed in the angular and temperature dependences of the field H/sub c/2. The data obtained by the measurements are compared to the results obtained on the basis of a model that uses solutions of the Ginzburg--Landau equations with anisotropic masses and takes into account the superlattice.