摘要
采用简单的化学镀方法,在相对低的温度下制备了具有核-壳结构的SiC-Ni纳米复合颗粒。XRD和TEM分析结果表明,纳米Ni晶吸附在SiC颗粒表面,可以形成一层连续且致密的Ni包覆层。基于化学镀和催化理论,初步分析了化学镀核壳结构形成机理。利用波导法研究了纳米SiC颗粒和复合颗粒在8～12 GHz的微波介电特性。研究结果表明,复合颗粒的介电常数实部(ε′)和介电损耗角正切值(tanδ=ε″/ε′)都明显增强,并给出相应的理论模型。
A nanoscale core-shell structure ofβ-SiCp-Ni has been prepared at lower temperature by a simple and convenient electroless plating approach.The core-shell nanoparticles have been characterized by means of XRD and TEM.The results show thatβ-SiC nanoparticles （β-SiCP） are coated by a uniform and continuous nickel shell.The mechanism based on the theory of electroless plating and palladium catalysis has been discussed in details about core-shell structure ofβ-SiCP-Ni.Dielectric permittivities of the original silicon carbide nanoparticles （β-SiCP） and nickel-coatedβ-SiCP in paraffin wax are measured respectively in the GHz frequency range from 8 to 12 GHz.The real part and dielectric loss tangent of the nickel-coatedβ-SiCP are significantly enhanced.The origin of the enhancement is theoretically discussed,and also explained by the change of surface electrical conduction behavior ofβ-SiCP and nickel-coatedβ-SiCP.
基金
科技部863资助课题(2002AA305509)
国家自然科学基金
教育部博士点基金(2004007021)
黑龙江省自然科学基金(E2004-20)
关键词
SiC-Ni核壳结构
化学镀
SIC
介电性能
core-shell structure of silicon carbide and nickel
electroless plating
SiC
dielectric property
