Ge掺杂对TiO_2-Nb_2O_5-CaCO_3压敏陶瓷结构及性能的影响  

Ge-doping in TiO_2-Nb_2O_5-CaCO_3 Varistor Ceramics: Structure and Property

作　　者：康昆勇 徐开蒙[1,2,3] 刘灿 杨晓琴[1,2,3] 郑志锋 KANG Kun-Yong;XU Kai-Meng;LIU Can;YANG Xiao-Qin;ZHENG Zhi-Feng(Faculty of Materials Science and Engineering, Southwest Forestry University, Kunming 650224, China;Yunnan Provincial Engineering Laboratory for Highly-Efficient Utilization of Biomass, Southwest Forestry University, Kunming 650224, China;Yunnan Provincial University Key Laboratory for Biomass Chemical Refinery ＆ Synthesis, Southwest Forestry University, Kunming 650224, China)

机构地区：[1]西南林业大学材料科学与工程学院,昆明650224 [2]西南林业大学云南省生物质高效利用工程实验室,昆明650224 [3]西南林业大学云南省高校生物质化学炼制与合成重点实验室,昆明650224

出　　处：《无机材料学报》2018年第4期447-452,共6页Journal of Inorganic Materials

基　　金：国家自然科学基金(31670599)~~

摘　　要：TiO_2压敏电阻是一种典型的非线性电流-电压电子器件,本文研究了Ge掺杂对TiO_2-Nb_2O_5-CaCO_3压敏陶瓷的非线性系数α和压敏电压EB的影响。采用传统的球磨-成型-烧结方法成功制备Ge掺杂TiO_2-Nb_2O_5-CaCO_3压敏陶瓷,用压敏直流参数仪测试样品的非线性系数α、压敏电压EB和漏电流JL等电学性质,并根据相关公式计算样品平均势垒高度。XRD、XPS、SEM和STEM分析表明,Ge掺杂显著改变TiO_2-Nb_2O_5-CaCO_3压敏陶瓷微结构,提高非线性系数α和减小压敏电压EB。当施主Nb_2O_5和受主CaCO_3掺杂浓度分别为0.5mol%时,掺杂1.0mol%Ge的压敏陶瓷获得了最高的非线性系数和较低的压敏电压(α=10.6,EB=8.7 V/mm),明显优于不掺杂Ge的TiO_2-Nb_2O_5-CaCO_3压敏陶瓷。此外,Ge熔点较低,作为烧结助剂可以降低陶瓷的烧结温度,TiO_2-Nb_2O_5-CaCO_3-Ge压敏陶瓷最佳烧结温度是1300℃。TiO2 varistors are typical electronic devices with nonlinear current-voltage property fabricated from TiO2 ceramics. This study investigated the influence of Ge doping on the nonlinear coefficient a and the breakdown electric field EB of TiO2-Nb2Os-CaCO3 varistor ceramics. TiO2-Nb2O5-CaCO3 varistor ceramics doped with Ge were successfully prepared by using traditional method of ball milling-molding-sintering. The electrical performance, including nonlinear coefficient a, breakdown electric field EB, and leakage current JL, was tested with a varistor-direct current-parameter instrument. Average barrier height φB of each sample was calculated by relevant formula. Analysis of X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, and scanning transmission electronic microscopy demonstrated that Ge doping notably changed the microstructure of TiO2-Nb2O5-CaCO3 ceramics, thereby increasing a and decreasing EB. When Nb2O5 and CaCO3 doping content were 0.5mol%, the TiO2-Nb2O5-CaCO3 varistor ceramics doping with 1.0 mol% Ge exhibited high a （10.6）, low EB （8.7 V/mm）, and highest φB （1.73 eV）, superior to previous published findings. Furthermore, Ge with low melting point as sintering aid could reduce the sintering temperature of the varistor ceramics, with optimal sintering temperature at 1300℃.

关 键 词：TIO2压敏陶瓷 非线性系数 压敏电压 Ge 

分 类 号：TP204[自动化与计算机技术—检测技术与自动化装置]