Field dependent neutron diffraction study in Ni50Mn38Sb12 Heusler alloy

TL;DR

This neutron diffraction study investigates the temperature and magnetic field effects on the structural and magnetic transitions in Ni50Mn38Sb12 Heusler alloy, revealing field-induced reverse martensitic transition and phase fraction changes.

Contribution

It provides detailed insights into the magneto-structural phase transitions and the field dependence of phase fractions in Ni50Mn38Sb12 Heusler alloy using neutron diffraction.

Findings

Field induces reverse martensitic transition.

Martensite phase fraction is 85% below transition.

Magnetic moments are insensitive to field at 3 K.

Abstract

In this paper, we present temperature and field dependent neutron diffraction (ND) study to unravel the structural and the magnetic properties in Ni50Mn38Sb12 Heusler system. This alloy shows martensitic transition from high temperature austenite cubic phase to low temperature martensite orthorhombic phase on cooling. At 3 K, the lattice parameters and magnetic moments are found to be almost insensitive to field. Just below the martensitic transition temperature, the martensite phase fraction is found to be 85%. Upon applying the field, the austenite phase becomes dominant, and the field induced reverse martensitic transition is clearly observed in the ND data. Therefore, the present study gives an estimate of the strength of the martensite phase or the sharpness of the martensitic transition. Variation of individual moments and the change in the phase fraction obtained from the analysis of the ND data vividly show the change in the magneto-structural state of the material across the transition.