Superconductivity and short range order in metallic glasses Fe$_{x}$Ni$_{1-x}$Zr$_{2}$

TL;DR

This study investigates how varying Fe content in FeNiZr metallic glasses affects their superconducting properties and short-range order, revealing microstructural changes through magnetization and resistance measurements.

Contribution

It provides new insights into the relationship between Fe content, short-range order, and superconductivity in metallic glasses, using combined magnetic and transport measurements.

Findings

Superconducting critical temperature varies with Fe content.

Distinct magnetic hysteresis and fluctuations indicate changes in short-range order.

High Fe content correlates with altered vortex pinning and microstructure.

Abstract

In amorphous superconductors, superconducting and vortex pinning properties are strongly linked to the absence of long range order. Consequently, superconductivity and vortex phases can be studied to probe the underlying microstructure and order of the material. This is done here from resistance and local magnetization measurements in the superconducting state of Fe$_{x}$Ni$_{1-x}$Zr$_{2}$ metallic glasses with $0\leq x \leq 0.6$. Firstly, we present typical superconducting properties such as the critical temperature and fields and their dependence on Fe content in these alloys. Then, the observations of peculiar clockwise hysteresis loops, wide double-step transitions and large magnetization fluctuations in glasses containing a large amount of Fe are analyzed to reveal a change in short range order with Fe content.