Irreversibility of field-induced magnetostructural transition in NiCoMnSb shape memory alloy revealed by magnetization, transport and heat capacity studies

TL;DR

This study demonstrates that magnetic field-induced martensitic to austenite phase transition in NiCoMnSb shape memory alloy is irreversible at the critical temperature, with magnetization, resistivity, and heat capacity confirming the phenomenon.

Contribution

It reveals the irreversibility of the field-induced martensitic transition in NiCoMnSb, highlighting the role of energy fluctuations in phase nucleation and growth.

Findings

Large field-induced irreversibility observed in resistivity, magnetization, and heat capacity.

Transition from martensitic to austenite phase is non-reversible at the critical temperature.

No coexistence of phases in the irreversibility regime.

Abstract

The effects of magnetic field on the martensitic transition have been studied in Ni45Co5Mn38Sb12. We find a large field-induced irreversibility in this system, as revealed by the field dependence of resistivity, magnetization, and heat capacity data. At the critical temperature, the field-induced conversion of the martensitic to austenite phase is not reversible under any field variation. At this temperature any energy fluctuation induces nucleation and growth of the equilibrium austenite phase at the expense of the metastable martensitic phase and gets arrested. All these three measurements completely rule out the coexistence of austenite and martensitic phases in the irreversibility regime.