单晶硅表面沉积Ni-Co-P镀层的显微结构和性能

Microstructures and Properties of Electroless Ni-Co-P Coatings on Si (100) Substrate

摘要:

采用化学镀工艺在p型(100)单晶硅表面制备了2种Ni-Co-P镀层，对比分析其显微结构和性能。结果表明：Ni48Co46P6镀层为非晶和纳米晶混合结构，表面均匀分布着直径0.2 ~ 3.5 μm的球状团簇。而Ni22Co74P4镀层为单相密排六方结构，含有强烈的(0002)晶面择优取向，表面由纳米级梭状团簇和微米级苞状团簇混合而成。在3.5% NaCl溶液中，2种镀层均表现出活化-钝化-过钝化的腐蚀行为，其中Ni48Co46P6镀层的耐蚀性能较好。而在1.0% H2SO4溶液中，2种镀层的耐蚀性能均大幅下降。与Ni48Co46P6镀层相比，Ni22Co74P4镀层的室温电阻率略有降低，饱和磁化强度和矫顽力显著升高

Abstract:

Two types of Ni-Co-P coatings were synthesized by electroless deposition on p-type Si (100) substrates. Microstructures and properties of the coatings were studied and compared. A mixture of amorphous and nanocrystal structures was found in Ni48Co46P6 coatings, while Ni22Co74P4 coatings contained a nanocrystalline hexagonal closed packed phase with a strong (0002) texture. Surfaces of both coatings were composed of clusters. In Ni48Co46P6 coatings, the clusters were 0.2 ~ 3.5 μm nodules that distributed uniformly, whereas in Ni22Co74P4 coatings there were nano-sized shuttle clusters mixed with micro-sized bud clusters. Both coatings exhibited activation-passivation-transpassivation processes in 3.5% NaCl solution, and Ni48Co46P6 coatings showed a better corrosion resistance. However, corrosion resistance of both Ni-Co-P coatings was decreased remarkably in 1.0% H2SO4 solution. Compared with Ni48Co46P6 coatings, Ni22Co74P4 coatings showed a much improved saturation magnetization and coercivity with a slightly decreased electrical conductivity.