Mastering disorder in a first-order transition by ion irradiation

TL;DR

This paper investigates how ion irradiation modifies the magneto-structural phase transition in MnAs thin films, highlighting the role of ion-induced disorder and elastic collisions in suppressing thermal hysteresis and transition sharpness.

Contribution

It demonstrates the specific effects of ion bombardment on phase transition properties, emphasizing the mechanisms of disorder and elastic interactions involved.

Findings

Ion irradiation suppresses thermal hysteresis.

Disorder at the transition correlation length affects sharpness.

Elastic coupling influences phase coexistence patterns.

Abstract

The effect of ion bombardment on MnAs single crystalline thin films is studied. The role of elastic collisions between ions and atoms of the material is singled-out as the main process responsible for modifying the properties of the material. Thermal hysteresis suppression, and the loss of sharpness of the magneto-structural phase transition are studied as a function of different irradiation conditions. While the latter is shown to be associated with the ion induced disorder at the scale of the transition correlation length, the former is related to the coupling between disorder and the large-scale elastic field associated with the phase coexistence pattern.