【摘要】 研究了Sr对新型 (Co ,Nb)掺杂SnO2 压敏材料微观结构和电学性质的影响 .当SrCO3的含量从零增加到1 5 0mol%时 ,(Co ,Nb)掺杂SnO2 压敏电阻的击穿电压从 2 4 0V mm猛增到 14 82V mm .样品的微观结构分析发现 ,当SrCO3的含量从零增加到 1 5 0mol%时 ,SnO2 的晶粒尺寸迅速减小 .晶界势垒高度测量揭示 ,SnO2 晶粒尺寸的迅速减小是击穿电压急剧增高的主要原因 .对Sr含量增加引起SnO2 晶粒减小的根源进行了解释 .掺杂 1 5 0mol%SrCO3的SnO2 压敏电阻非线性系数为 2 1 4 ,击穿电压高达 14 82V mm更多还原

【Abstract】 The effect of Sr on the microstructure and nonlinear electrical properties of the (Co, Nb) doped SnO 2 varistors was investigated. The breakdown voltage of the SnO 2 based varistors increased significantly from 240 to 1482V/mm with increasing SrCO 3 concentration from 0 to 1.50 mol%. Measurement of the barrier height at grain boundaries reveal that the significant decrease of the SnO 2 grain size with increasing SrCO 3 concentration from 0 to 1.50 mol%, is the reason of the enhancement of the breakdown voltage. The origin for the reduction of SnO 2 grain size with increasing SrCO 3 concentration was explained. The 1.50 mol% SrCO 3 doped SnO 2 varistor with ultrahigh breakdown voltage (1482V/mm) and larger nonlinear coefficient α(21.4) is a candidate used in the ultrahigh voltage protection system.更多还原