Phase stability and superconducting properties of YPd2B2CYPt2B2C solid solutions

Abstract

We tried the substitution of Pt for Pd in superconducting YPd2B2C in order to stabilize the phase. YPd2B2CYPt2B2C solid solutions were prepared by arc melting, and phase stability and superconducting properties were investigated. The superconducting phase and the corresponding diffraction pattern were observed in samples prepared from the starting compositions of Y(Pd1 − xPtx)2B2C with x ≥ 0.2. Two phases with different critical temperatures (Tc) (high-Tc and low-Tc phases) were observed in the as-melted Pt rich samples. Annealing of these solid solutions in the range of x ≥ 0.4 resulted in the disappearance of the high-Tc phase and a substantial increase of the volume fraction of the low-Tc phase was obtained. In the range of x ≥ 0.7 almost a single phase of the low-Tc phase was obtained. The superconducting transition was sharpened by the annealing, which was attributed to the disappearance of the high-Tc phase. Tc of the Y(Pd, Pt)2B2C compound decreased monotonically with the increase of Pt content.