Abstract
Kr^+ and Ar^+ ions were irradiated onto CrPt_3 ordered alloy films fabricated by a magnetron sputtering deposition followed by an appropriate heat treatment, and the change of the magnetic properties of the CrPt_3 films were examined. For 30keV Kr^+ ion irradiation, the magnetic order (magnetization) of the CrPt_3 was found to be completely suppressed by a quite low ion dose of 2x10^<14>ions/cm^2 due the phase change from L1_2 ordered CrPt_3 phase to disordered fcc phase. Moreover, it was found that such a low ion dose of 2x10^<14>ions/cm^2 has no effect on the lattice distortion of the CrPt_3 contributing to its large uniaxial anisotropy. Magnetic force microscope image of the ion-beam patterned CrPt_3 fabricated using electron beam lithography showed clear magnetic contrast in non-irradiated regions, while no magnetic contrast in irradiated regions, even in the fabrication size of 180nm x 180nm pitch. Ion-beam patterned CrPt_3 disk with 600nm patterning pitch was fabricated by Ar^+ ion irradiation through nano-imprinted masks. The read-back waveform taken from the patterned CrPt_3 disk showed sharp signal transition between irradiated and non-irradiated regions.
