Swift heavy ion induced magnetic phase transition of Fe-Rh alloy

We report the effects of swift heavy ion irradiation on structure and magnetic properties of Fe-50at.%Rh alloys. The alloys are irradiated with 120-200 MeV heavy ions (Ni, Kr or Xe) at room temperature. Before and after the irradiations, the magnetization and the lattice parameter are measured by using superconducting quantum interference device (SQUID) and X-ray diffractometer (XRD), respectively. The lattice parameter at room temperature increases by about 0.3% and antiferromagnetic-ferromagnetic transition temperature decreases below 5 K by the irradiations. Effects of electronic excitation due to swift heavy ions on the change in magnetic properties and lattice structure are discussed.