Superconducting properties of C8KHg have been investigated by AC magnetic susceptibility measurements. The measured values of Tc are 1.90 K and 1.70 K for two samples. From the measurements under DC magnetic field, the superconductivity is found to be the type II in all the field directions. Hc2 is markedly anisotropic, but the angular dependence of Hc2 is fairly well understood by means of the 3D anisotropic effective mass model. The characteristic parameter γ is too large, e.g. 64 or 76, to apply the 2D Josephson-coupling model. So, C8KHg is regarded as a 3D superconductor with a very large anisotropy rather than a 2D one. As the obtained effective mass ratio is as large as 940 or 920, the electronic band structure of C8KHg seems more anisotropic than that of C8K. In C4KHg, superconductivity has not been found above 1.5 K.
ASJC Scopus subject areas
- Physics and Astronomy(all)