Modulated structure in the martensite phase of Ni1.8Pt0.2MnGa: a neutron diffraction study

TL;DR

This study investigates the modulated structure of Ni1.8Pt0.2MnGa's martensite phase using neutron diffraction, revealing a volume-conserving transformation and increased magnetic moments, suggesting potential for magnetic field-induced strain.

Contribution

It provides detailed neutron diffraction analysis of Ni1.8Pt0.2MnGa's martensite structure, highlighting its magnetic properties and structural modulation.

Findings

Identified 7M orthorhombic modulated structure in martensite

Volume change between phases is less than 0.5%

Magnetic moment in martensite is higher than in Ni2MnGa

Abstract

7M orthorhombic modulated structure in the martensite phase of Ni1.8Pt0.2MnGa is reported by powder neutron diffraction study, which indicates that it is likely to exhibit magnetic field induced strain. The change in the unit cell volume is less than 0.5% between the austenite and martensite phases, as expected for a volume conserving martensite transformation. The magnetic structure analysis shows that the magnetic moment in the martensite phase is higher compared to Ni2MnGa, which is in good agreement with magnetization measurement.