초록
An artificially modulated magnetic Co/Pd multilayer is one of the promising candidates for high density magneto-optic (MO) recording media, due to a large Kerr rotation angle in the wavelength of a blue laser beam. However, since multilayer structure, as well as amorphous structure, is a non-equilibrium state in terms of free energy and a MO recording technology is a kind of thermal recording which is conducted around Curie temperature (Tc) of the recording media, when the Co/Pd mulilayer is used for the MO recording media, changes in the magnetic properties are occurred as the amorphous structure do. Therefore, the assessment of the magnetic properties in the Co/Pd multilayer during interdiffusion is crucially important both for basic research and applications. As the parameter of the magnetic properties in this research, saturation magnetization and perpendicular magnetic anisotropy energy of the Co/Pd multilayer are measured in terms of Ar sputtering pressure and heat treatment temperature. Form the results of the research, we find out that the magnetic exchange energy between Co and Pd sublayers strongly affects the changes in the magnetic properties of the Co/Pd multilayers during the interdiffusion in ferromagnetic state. This discovery will provide the understanding of the magnetic exchange energy in the Co/Pd multilayer structure and suggest the operating temperature range for MO recording in the Co/Pd multilayer for the basic research and applications, respectively.