Influence of pyrolysis temperature on structure and dielectric properties of polycarbosilane derived silicon carbide ceramic  

热解温度对聚碳硅烷转化SiC陶瓷结构及介电性能的影响(英文)

作　　者：丁冬海[1,2] 周万城[1] 周璇[1] 罗发[1] 朱冬梅[1] 

机构地区：[1]西北工业大学凝固技术国家重点实验室,西安710072 [2]西安建筑科技大学材料与矿资学院,西安710055

出　　处：《Transactions of Nonferrous Metals Society of China》2012年第11期2726-2729,共4页中国有色金属学报（英文版）

基　　金：Project (50572090) supported by the National Natural Science Foundation of China;Project (KP200901) supported by the Fund of the State Key Laboratory of Solidification Processing, China

摘　　要：β-SiC ceramic powders were obtained by pyrolyzing polycarbosilane in vacuum at 800-1200 °C. The β-SiC ceramic powders were characterized by TGA/DSC, XRD and Raman spectroscopy. The dielectric properties of β-SiC ceramic powders were investigated by measuring their complex permittivity by rectangle wave guide method in the frequency range of 8.2-18 GHz. The results show that both real part ε′ and imaginary part ε″ of complex permittivity increase with increasing pyrolysis temperature. The mechanism was proposed that order carbon formed at high temperature resulted in electron relaxation polarization and conductance loss, which contributes to the increase in complex permittivity.采用真空高温裂解聚碳硅烷法制备β-SiC陶瓷粉末，并对热解产物进行TGA/DSC、XRD和拉曼光谱表征。通过矩形波导法测量β-SiC陶瓷粉末与石蜡复合材料在8.2-18 GHz下的复介电常数来研究其介电性能。结果表明：复介电常数的实部与虚部均随着热解温度的升高而增大。高温下产生的石墨碳引起的电子松弛极化及电导损耗是复介电常数的实部与虚部增大的主要原因。

关 键 词：silicon carbide ceramic polycarbosilane derived SiC dielectric properties pyrolysis temperature free carbon complexpermittivity 

分 类 号：TQ174.6[化学工程—陶瓷工业]