Magnetostructural Transformation and Magnetoresponsive Properties of MnNiGe1-xSnx Alloys

TL;DR

This study explores how Sn substitution in MnNiGe alloys influences their structural and magnetic phase transformations, leading to enhanced magnetoresponsive effects and potential applications in magnetic cooling.

Contribution

It provides new insights into the magnetostructural transformations and magnetoresponsive properties of MnNiGe1-xSnx alloys with varying Sn content.

Findings

Sn substitution decreases martensitic transformation temperature from 460 to 100 K.

Sn substitution induces a transition from AFM spiral to antiparallel AFM in martensite.

Enhanced magnetocaloric and magnetoresponsive effects observed with Sn substitution.

Abstract

The martensitic and magnetic phase transformations in MnNiGe1-xSnx (0 \leq x \leq 0.200) alloys were investigated using X-ray diffraction (XRD), differential thermal analysis (DTA) and magnetization measurements. Results indicate that the increasing Sn substitution in MnNiGe1-xSnx results in (i) decrease of martensitic transformation temperature from 460 to 100 K and (ii) conversion of AFM spiral to antiparallel AFM strcuture in martensite. Based on these, the remarkable magnetic-field-induced PM/spiral-AFM and FM/AFM magnetostructural transformations and, large positive and negative magnetocaloric effects are obtained. The magnetoresponsive effects of MnNiGe1-xSnx alloys are enhanced by Sn substitution. A structural and magnetic phase diagram of MnNiGe1-xSnx alloys has been proposed.