纳米晶Co-7.31%P化学镀层的耐蚀性与磁性

Corrosion Resistance and Magnetic Properties of Electroless Nanocrystalline Cobalt-Phosphorous Coatings

采用化学镀工艺在p型(100)单晶硅表面制备了含P约7.31%(原子分数)的Co-P镀层,研究了镀层的显微结构、耐蚀性能和磁性。结果表明:Co-7.31%P镀层为密排六方结构,平均晶粒尺寸为24 nm,表面均匀分布着微米级枯叶状团簇,团簇之间存在纳米级孔隙;镀层在10.0%NaOH溶液中耐蚀性最好,3.5%NaCl溶液中次之,1.0%H2SO4溶液中最差;室温下镀层表现出明显的磁各向异性,易磁化方向的饱和磁化强度和矫顽力分别为138.5 A.m2/kg和25 870.0 A/m。

Co-P coatings with 7.31% P(atomic fraction) were prepared on p-type Si(100) substrates by electroless plating.The microstructures,corrosion resistance and magnetic properties of as-plated Co-P alloy coatings were studied.Results indicate that Co-7.31% P coatings consist of closely packed hexagonal phase with an average grain size of 24 nm.Micro-sized dead-leaf-shaped clusters and nano-sized pores are distributed uniformly on the coating surface and there exist nanoscale pores between the clusters.As-plated Co-P alloy coatings show the best corrosion resistance in 10.0% NaOH solution,fair corrosion resistance in 3.5% NaCl solution,and the poorest corrosion resistance in 1.0% H2SO4 solution.Besides,as-plated Co-P alloy coatings possess prominent magnetic anisotropy,showing a saturation magnetization of 138.5 A·m2/kg and a coercivity of 25 870.0 A·m along the parallel direction in which magnetization is easy to occur.