Superconducting and fermi surface properties of single crystal Zr2Co

Abstract

We succeeded in growing single crystals of a superconductor Zr2Co with the tetragonal structure by the Bridgman method and carried out electrical resistivity, magnetic susceptibility, magnetization, specific heat, and de Haas- van Alphen (dHvA) experiments. Superconductivity is a characteristic revealing that the electronic specific heat at 1.45K in the form of Ce=T in the superconducting state increases not linearly but as a function of √ H p up to a magnetic field close to the upper critical field Hc2 = 11 kOe. The superconducting transition temperature Tsc is found to increase markedly with increasing pressure from Tsc = 5.2K at ambient pressure to 9.5K at 8 GPa. From the dHvA experiment, several kinds of dHvA branches are detected, which are well explained by the results of the energy band calculation. The main conduction electrons are Zr-4d and Co-3d electrons.