Hydrostatic Pressure Effect on the Superconducting Transition Temperature and the Transport Properties of NbSe₂

抄録

Pressure dependence of the superconducting transition temperature, T_c, the electrical resistivity, ρ, and of the Hall coefficient, R_H, in the layered compound NbSe₂ were measured. A low-temperature phase was found to be stable in a range of temperature below 26 K and of pressure below 1 kb, with T_c=7.16 K and negative sign of R_H, while T_c of the high temperature (2H) phase is 7.35 K and R_H being positive in sign. It is concluded, contrary to the current idea, that changes in the intralayer parameters are important in explaining the behavior of T_c, ρ, and R_H under pressure, at least equally to the change in the van der Waals gap distance in layered compounds.