Electronic structure and glass forming ability in early and late transition metal alloys

TL;DR

This study reveals a strong correlation between electronic structure changes upon crystallization and glass forming ability in various transition metal alloys, providing a simple criterion for selecting high GFA compositions.

Contribution

It demonstrates that changes in magnetic susceptibility and electronic structure can predict glass forming ability across different transition metal alloys.

Findings

Small {}hi}exp correlates with high GFA.

Good correlation between {}hi}exp and critical casting thickness.

Applicability of {}hi}exp criterion to various metal-metal MGs.

Abstract

A correlation between the change in magnetic susceptibility ({\Delta}\c{hi}exp) upon crystallization of Cu-Zr, Hf metallic glasses (MG) with their glass forming ability (GFA) observed recently is found to apply to Cu-Ti and Zr-Ni alloys, too. In particular, a small {\Delta}\c{hi}exp , which reflects similar electronic structures, ES, of glassy and corresponding crystalline alloys, corresponds to high GFA. Here, we studied {\Delta}\c{hi}exp in five Cu-Ti and four Cu-Zr and Ni-Zr MGs. The fully crystalline final state of all alloys was verified from X-ray diffraction patterns. The variation of GFA with composition in Cu-Ti, Cu-Zr and Cu-Hf MGs was established from the variation of the corresponding critical casting thickness, dc. Due to the absence of data for dc in Ni-Zr MGs their GFA was described by using empirical criteria, such as the reduced glass transition temperature. A very good correlation between {\Delta}\c{hi}exp and dc (and/or other criteria for GFA) was observed for all alloys studied. The correlation between the ES and GFA showed up best for Cu-Zr and NiZr2 alloys where direct data for the change in ES ({\Delta}ES) upon crystallization are available. The applicability of the {\Delta}\c{hi}exp ({\Delta}ES) criterion for high GFA (which provides a simple way to select the compositions with high GFA) to other metal-metal MGs (including ternary and multicomponent bulk MGs) is briefly discussed.