Magnetic, magneto-optical, and transport properties of ferromagnetic shape-memory Ni₂MnGa alloy

The magnetic, transport, and magneto-optical properties of Ni₂MnGa alloy in the martensitic and austenitic states were investigated. The temperature dependence of resistivity shows kinks at the structural and ferroparamagnetic transitions. The temperature dependence of magnetization was also investigated for both the bulk and the film. It was shown that the lack of crystallinity in the amorphous Ni₂MnGa alloy films leads to the loss of ferromagnetic order above 4 K. The nature of the interband absorption peaks in the optical-conductivity spectra and in the absorptive part of off-diagonal components of the dielectric function for the authentic state of Ni₂MnGa alloy was elucidated. © 2003 American Institute of Physics.