Studies of the pressure-dependent superconducting states of HoNi2B2C and DyNi2B2C

Abstract

We have investigated the pressure dependence of the superconducting states of high-quality single crystals of HoNi2B2C and DyNi2B2C through resistivity and magnetization measurements. When a pressure is applied, the superconducting transition temperature, T-e, of HoNi2B2C is suppressed while the Neel temperature, T-N, increases with pressure. At the same time, a reentrance behavior found in the temperature dependence of the upper critical field, H-c2(T), of HoNi2B2C decreases with increasing pressure and eventually disappears completely above 8.3 kbar. This observation is in sharp contrast with the weak pressure dependence found in H-c2(T) of DyNi2B2C. Our experimental findings can be understood in terms of a Ginzburg-Landau type analysis.