Phase coexistence induced by cooling across the first order transition in Ni–Co–Mn–Sb shape memory alloy

Abstract

The first order austenite to martensitic transition in the off-stoichiometric Heusler alloy Ni–Co–Mn–Sb has been studied using magnetization, electrical resistivity, and heat capacity measurements with different field cooling protocols and thermal cyclings. The coexistence of high temperature, high magnetic austenite phase along with the low temperature and low magnetic martensitic phase after field cooling has been confirmed by all these measurements. The time dependence of these data quite vividly illustrates the metastability of the supercooled/superheated phase in the disorder-broadened first order transition.