Superconducting FeSe1-xTex Single Crystals Grown by Optical Zone-Melting Technique

TL;DR

This paper presents a novel optical zone-melting method for growing high-quality, homogeneous FeSe1-xTex superconducting single crystals with improved control and efficiency, reducing compositional inhomogeneity and transition width.

Contribution

The study introduces an optical zone-melting technique for FeSe1-xTex crystal growth, demonstrating high crystallinity, compositional uniformity, and reduced superconducting transition width.

Findings

Crystals show high crystallinity with no phase separation.

Homogeneity in composition achieved through heat treatment.

Transition width of superconductivity reduced to about 2 K.

Abstract

A new approach to grow FeSe1-xTex single crystals with optical zone-melting technique was successfully employed. Crystals with actual composition 0.4 < x < 1.0 all show high crystallinity with no phase separation. The ability to visually observe the locally heated melt, and ease of use and control of the image furnace make this method a promising and time-efficient way for obtaining high-quality FeSe1-xTex crystals. Our results indicate that with adequate heat treatment, the non-uniform distribution of Se and Te atoms in crystal lattice can be effectively eliminated, while the transition width of superconductivity can be reduced to about 2 K, which suggest the crystals are homogeneous in nature.