Analysis of local chemical and structural inhomogeneities in FeySe1−xTex single crystals

Abstract

Co-existence of superconductivity and magnetism has been reported in certain regions of the Fe(Se,Te) phase diagram. Here, we address the key question of whether these different properties occur simultaneously within a homogeneous crystal or whether a “two-phase” description is more appropriate. Extensive microstructural analysis suggests that a Te-rich sample exhibiting both bulk superconductivity and magnetic order contains significant chemical and structural inhomogeneity, suggesting that the “two-phase” explanation may be valid in this sample. The high-resolution electron backscatter diffraction (HR-EBSD) technique has been used to map local changes in lattice parameter very precisely in these compounds.