Magnetic Properties of Superconducting Layered Compounds.

摘要

The results of an investigation of the fluctuation-induced diamagnetism and upper critical fields of superconducting layered compounds are presented. Compounds studied include TaS2 and TaS(1.6)Se(0.4) intercalated with collidine, pyridine, or aniline, having layer separations of 3, 6, and 12 A respectively, and the unintercalated compounds TaS(1.6)Se(0.4) and NbSe2. Susceptibility above T sub c for TaS2(pyridine)1/2 and NbSe2 was measured in fields up to 300 G with a superconducting quantum magnetometer. Extensive measurements of (H sub C2) as a function of field orientation and temperature were made with an ac susceptibility technique, in fields to 120 kG. The critical field anisotropy however, is found to depend only weakly on the separation between metallic layers.