Effect of the tellurium for selenium substitution on the phase composition and electrical resistivity of Fe7(Se1-xTex)8

Abstract

The discovery of Fe(Se, Te)-type superconductors has attracted much attention due to their simplest crystal structure among the new families of iron-based layered compounds. However, the Fe(Se, Te) samples often exhibit an impurity hexagonal phase of the NiAs-type together with the main superconducting phase having a tetragonal PbO-type phase [1]. The aim of the present work is to study how the coexistence of the tetragonal and hexagonal phases in the Fe7(Se,Te)8 samples influences their superconducting properties bearing in mind the limited solubility of tellurium in Fe7(Se,Te)8.