Ag对CoPt/Ag纳米复合膜的结构与磁性的影响

采用直流磁控溅射的方法制备了一系列(CoPt/Ag)_n多层膜，然后在不同温度下 进行了退火处理，并对其结构和磁性做了初步的表征，研究了Ag的含量以及薄膜中每一单元 厚度与总厚度对退火后薄膜的结构以及磁性能的影响.结果表明，膜厚较薄时(大约20 nm)有 利于薄膜沿(001)取向生长，Ag的加入不但能够抑制CoPt晶粒的过分长大还可以诱导薄膜的( 001)取向，使退火后的薄膜在垂直于膜面方向上的矫顽力大大增强.对于特定组分为Co ₄₀Pt₄₃Ag₁₇的薄膜，经600℃退火后已经显示了明显的(001) 取向，垂直于膜面方向上的矫顽力为5.6×10⁵ A/m，饱和磁化强度为0.65T, 并 且磁滞回线具有很好的矩形度，剩磁比(s)为0.95. 关键词： 磁记录材料 磁性薄膜 CoPt/Ag纳米复合膜

Effect of Ag on the structure and magnetic properties of CoPt/Ag nanocomposite films

CoPt/Ag nanocomposite films were prepared by magnetron sputtering. The dependenc e of texture and magnetic properties on film thickness, bilayer thickness, Ag at omic fraction and annealing conditions is investigated. Films with thickness bel ow 20 nm are apt to form (001) orientation. The existence of the Ag in the film plays a dominant role in inducing the (001) texture of the film besiles suppress ing the growth of the CoPt grains during annealing. The Co₄₀Pt₄₃ Ag₁₇ film after annealing at 600℃ exhibits a large perpendicul ar coercivity of H_C=5.6×10⁵ A/m, a large saturation magne tization of M_S=0.65T and a squareness of s=0.95 of the hysteresis loo p.