真空退火Co/Pt多层膜的结构、磁及磁光特性分析

Analysis on Structure, Magnetic and Magneto-Optical Properties of Vacuum Annealed Co/Pt Multilayer Films

本文用直流磁控溅射方法制备了Co／Pt多层膜，并对其进行了较为细致的真空退火处理，结果表明，适度的低温退火可增加Co／Pt多层膜的矫顽力，而并不削弱其磁滞克尔回线的矩形特征．当退火温度达到300℃以后，Co／Pt多层膜的矫顽力、垂直各向异性和克尔角将强烈下降，晶体结构的改善及应力的释放、晶粒的增长、层间原子扩散引起的Co层有效厚度减薄，进而居里温度的下降，分别是Co／Pt多层膜在低温、中温、高温退火过程中，磁及磁光性能变化的主要机制．

Co/Pt multilayer films were prepared by DC magnetron sputtering. Detailed vacuum annealiug was carried out on them. The results show that moderate annealing at lower temperature canimcrease the coercivity in Co/Pt multilayer films while not affect the shape of Kerr hysterisis loops.Annealing at or above 300℃ will cause the drastic decrease in coercivity, perpendiculax magneticanisotropy ajnd Kerr rotation in Co/Pt multilayer films. The improvement of crystal structure andthe release of stresses in films, the growth of grains, the reduction of effective Co layer thicknesscaused by atom diffusion between layers and further the decrease in Curie temperature are considered to be responsible for the changes in magnetic and magneto-optical properties for Co/Ptmultilayer films during lower, middle and higher temperature annealing, respectively.