【摘要】 利用聚碳硅烷与碳化硅粉混合,采用陶瓷工艺,低温烧成了碳化硅热敏电阻,其lnR-1/T关系具有鲜明的两段线性区.借助两相结构(α-SiC粉被聚碳硅烷热解得到的β-SiC所包围)的电流输运通道模型,用能带理论,计算了一个微导电单元的电导,从而对阻-温特性中反映的两种激活能的本质作出了解释.更多还原

【Abstract】 SiC thermistors have been prepared by mixing the polycarbosilane (PC) and SiC powders and then sintered at a low temperature with the ceramic technology. The relation InR-1/T of the samples prepared has two linear sections. The conductivity of one microunit has been calculated using the current transportation passage model of a two phase structure, in which the α-SiC powder is covered by a β-SiC layer from the pyrolysis of PC. It is believed that the conductivity in the low temperature range comes from the transportation of the β-SiC channel near the interface of β-SiC/α-SiC, that in the high temperature range (higher than 500~600K), from the electron thermal emission between α-SiC/α-SiC interfaces. The activation energy E1 corresponds to (T-qVD), and E2 to qVD.更多还原