Magnetostriction in Mn3CuN

Discovery of large magnetostriction in an antiperovskite Mn3CuN is reported. Mn3CuN undergoes the first-order transition from high-temperature (high-T) paramagnetic to low-temperature ferromagnetic (FM) phase at the Curie temperature T-C=143 K, accompanied by cubic-to-tetragonal structural deformation. In the tetragonally distorted FM phase, Mn3CuN, even in a polycrystalline form, expands 0.2% and shrinks 0.1% in the direction parallel and perpendicular to the external field of 90 kOe, respectively. This magnetostriction is possibly due to rearrangement of thermoelastic martensite variants by magnetic field, similar to FM Heusler alloys such as Ni2MnGa. (c) 2008 American Institute of Physics.