Cr_2O_3对(Co,Ta)掺杂的SnO_2压敏电阻电学特性的影响  

Effect of Cr_2O_3 on the electrical properties of (Co,Ta )-doped SnO_2 varistors

作　　者：臧国忠[1] 王矜奉[1] 陈洪存[1] 苏文斌[1] 王文新[1] 亓鹏[1] 王春明[1] 

机构地区：[1]山东大学物理与微电子学院,济南250100

出　　处：《科技通讯（上海）》2004年第1期79-82,共4页

基　　金：国家自然科学基金资助项目(50072013)

摘　　要：研究了Cr对(Co,Ta)掺杂的SnO2压敏材料电学性质的影响。当Cr2O3的含量从0增加到0.15mol%时,(Co,Ta)掺杂SnO2压敏电阻的击穿电压从206V/mm增加到493V/mm;1kHz时的相对介电常数从1968猛降至498;晶界势垒高度分析表明,SnO2晶粒尺寸的迅速减小是样品击穿电压增高、相对介电常数急剧降低和电阻率迅速增大的主要原因。对Cr含量增加引起SnO2晶粒减小的原因进行了解释。掺杂0.15mol%Cr2O3的SnO2压敏电阻非线性系数为24,击穿电压达498V/mm,在高压保护领域有很好的应用前景。The effects of Cr on the electrical properties of the(Co,Ta)-doped SnO 2 varistors were investigated.The breakdown voltag e of the SnO 2 based varistors increases from 206V/mm to 493V /mm,the relative dielectric constant decreases significantly from 1968to 498at 1kHz with Cr 2 O 3 concentra -tion increasing from 0to 0.15mol%.Measurement of the barrier height at g rain boundary reveal that the reason why breakdown voltage resistivity increases and relative die lectric constant decreases is the significant decrease of the SnO 2 grain size with Cr 2 O 3 concentration increasing from 0to 0.15mol%.The origin for the deduction of SnO 2 grain size with Cr 2 O 3 concentration increasing is explained.The0.15mol%Cr 2 O 3 -doped SnO 2 varistor with breakdown voltage of 493V /mm and larger nonlinear coefficient (α=24)is a candidate used in the high voltag e protection system.

关 键 词：压敏电阻 二氧化锡 势垒高度 非线性系数 电学性质 

分 类 号：TN304.21[电子电信—物理电子学] TN304.93