Martensitic Transition, Magnetic and Exchange Bias Properties in Mn Rich Heulser alloy Ribbons

Here we report the first order martensitic transition, microstructural, magnetic and exchange bias (EB) properties in Mn rich Mn50Ni50-xSnx (x=11) Heusler alloy ribbons, prepared by melt spinning method. A large EB field of around 213 Oe has been observed at 2 K, which is attributed to the exchange anisotropy present at the AFM/FM interfaces. The ribbon is found to exhibit the first order martensitic transition from high temperature austenite phase to low temperature martensite phase (i.e. at M-s similar to 74 K), at comparatively lower temperatures than that for the same bulk alloy. Curie temperature of the austenite phase (TCA) lies around room temperature. Observation of training effect strongly corroborates with the presence of EB in these ribbons. The effect of temperature on EB properties has also been studied.