Structure and superconductivity of two different phases of Re3W

TL;DR

This study reports the discovery and characterization of two distinct superconducting phases of Re3W with different crystal structures, transition temperatures, and physical properties, achieved through phase switching techniques.

Contribution

It is the first to identify and compare two different structural phases of Re3W and their superconducting properties using neutron diffraction and magnetic measurements.

Findings

One phase has a non-centrosymmetric cubic structure with Tc of 7.8 K.

The other phase has a hexagonal centrosymmetric structure with Tc of 9.4 K.

Both phases' critical fields, penetration depths, and coherence lengths were measured.

Abstract

Two superconducting phases of Re3W have been found with different physical properties. One phase crystallizes in a non-centrosymmetric cubic (alpha-Mn) structure and has a superconducting transition temperature, Tc, of 7.8 K. The other phase has a hexagonal centrosymmetric structure and is superconducting with a Tc of 9.4 K. Switching between the two phases is possible by annealing the sample or remelting it. The properties of both phases of Re3W have been characterized by powder neutron diffraction, magnetization, and resistivity measurements. The temperature dependence of the lower and the upper critical fields have been measured for both phases. These are used to determine the penetration depths and the coherence lengths for these systems.