Magnetoresistance and its relation to magnetization in Ni50Mn35Sn15 shape-memory epitaxial films

Abstract

The magnetoresistance (MR) of Heusler alloy Ni50Mn35Sn15 epitaxial films on MgO substrates is studied as a function of temperature T and magnetic field H. The large negative MR extends over martensitic transformation with maximum of −22% at 110 K. In martensitic and austenitic phase, the MR is −3% and −5%, respectively. We show that the MR is governed mainly by magnetization paraprocess at high magnetic fields and scales as the square of magnetization Δm(H,T)2.