Solid solubility and superconductivity of FeyTe1−xXx (X = Se, S)

Abstract

In this work, we present a systematic study on the solid solution, lattice parameters and superconductivity on the FeyTe1−xXx (X = Se, S) system. It has been found that the limit of the Te-site doping with Se and S is around 0.5 and 0.15, respectively. The solid solution with the Fe content changing is also measured in this work, and the single-phase region for preparing pure sample is presented. Based on the magnetic susceptibility measurements, we presented a three-dimensional graph for showing the variation of superconducting critical temperature as a function of both the chalcogen and Fe content in FeyTe1−xXx.