Synthesis and microwave dielectric properties of boron doped SiC powder by sol-gel method  

作　　者：李智敏 罗发 苏晓磊 朱冬梅 周万城 

机构地区：[1]State Key Laboratory of Solidification Processing,Northwestern Polytechnical University

出　　处：《中国有色金属学会会刊：英文版》2007年第A02期656-659,共4页Transactions of Nonferrous Metals Society of China

基　　金：Project(50572090) supported by the National Natural Science Foundation of China

摘　　要：Nano-SiC powders doped by B were synthesized through the carbothermal reduction of xerogels containing the tributyl borate. The results show that the 3C-SiC with minor phase of 6H-SiC is generated at 1 700 ℃,and that there are not the characteristic peaks of any boride in the XRD patterns,which indicates that the boron is available only on the crystallization of 3C-SiC. The Raman spectra of the samples also show the characteristic bands of 3C-and 6H-SiC at 788 and 965 cm-1. But the bands at 1 345 and 1 590 cm-1 are characteristic peaks of amorphous carbon materials. The intensities of peaks at 788 and 965 cm-1 increase with B content in Raman spectra,which also shift to higher wavenumber with the increasing B. The microstructure of SiC powder is composed of agglomerated particles with diameters ranging from 30 to 100 nm. The results of dielectric property show that the sample with 0.005 B has the largest values in ε′ and ε″ among the four samples due to the existence of the intrinsic defects. But the absence of the relaxation polarization leads to low values of all the samples.Nano-SiC powders doped by B were synthesized through the carbothermal reduction of xerogels containing the tributyl borate. The results show that the 3C-SiC with minor phase of 6H-SiC is generated at 1 700℃, and that there are not the characteristic peaks of any boride in the XRD patterns, which indicates that the boron is available only on the crystallization of 3C-SiC. The Raman spectra of the samples also show the characteristic bands of 3C- and 6H-SiC at 788 and 965 cm^-1. But the bands at 1 345 and 1 590 cm^-1 are characteristic peaks of amorphous carbon materials. The intensities of peaks at 788 and 965 cm increase with B content in Raman spectra, which also shift to higher wavenumber with the increasing B. The microstructure of SiC powder is composed of agglomerated particles with diameters ranging from 30 to 100 nm. The results of dielectric property show that the sample with 0.005 B has the largest values in e＇ and ε＂ among the four samples due to the existence of the intrinsic defects. But the absence of the relaxation polarization leads to low values of all the samples.

关 键 词：碳化硅粉末 制备方法 微波介电性能 硼掺杂 

分 类 号：TB383.3[一般工业技术—材料科学与工程]