Micromagnetic properties of Co/Pt multilayers deposited on various buffer layers

A study on the buffer layer dependence of the film texture, surface roughness, and magnetization re-versal process in Co/Pt multilayers prepared by dc magnetron sputtering is presented. Oxidized Si(100) wafer was covered with four different buffers: (A) 10 nm Cu, (B) 5 nm Ta/10 nm Cu, (C) 5 nm Ta/10 nm Cu/5 nm Ta, and (D) 5 nm Ta/10 nm Cu/5 nm Ta/10 nm Cu. The growth of [2 nm Pt/0.5 nm Co]×5/2 nm Pt on top of these buffer layers results in a large variation in the fcc (111) Co/Pt texture and surface mor-phology. All films have the perpendicular magnetic anisotropy but magnetization reversal process, stud-ied by the magnetooptic Kerr effect (MOKE) and magnetic force spectroscopy (MFM), strongly depends on the buffer used. Observation of magnetic domains evolution under a MOKE microscope allows one to calculate from magnetization relaxation curves average dispersion of energy barriers of the thermal acti-vated magnetization switching process. The application of MFM in external magnetic field allows one to follow the dynamics of direct and indirect magnetization switching procesess up to submicrometer scale.