Abstract
Magnetic and magneto-optical properties of (Co_<100-x>Fe_x)_<50>Pt_<50> alloy thin film were investigated for future high density magnetic or magneto-optical recording. A value of Ku on the order of 10^7erg/cc is found in Fe_<50>Pt_<50> alloy thin films. This large Ku has a closely relationship to ordering, and the M-O spectra of partially ordered phase are much different from that of disordered phase. The crystal structure of (Co_<43>Fe_<57>)_<54>Pt_<46> alloy thin film showed superlattice structure, and Ku was 1.8×10^7erg/cc. With increasing Fe content of this films, Ku and Ms tended to increase.