%0 Journal Article
%T Preparation and properties of the Ni/PTC ceramic composite<br>Ni/PTC陶瓷复合材料的制备和性能
%A LI Xiaolei QU Yuanfang MA Weibing ZHENG Zhanshen
%A <br>李晓雷
%A 曲远方
%A 马卫兵
%A 郑占申
%J 材料研究学报
%D 2004
%I 
%X In order to decrease the room-temperature resistivity of PTC materials, Ni/BaTiO$_{3}$ composite was synthesized by decomposition of NiC$_{2}$O$_{4}\cdot$2H$_{2}$O/BaTiO$_{3}$ precursor, which was prepared by precipitating nickel oxalate into BaTiO$_{3}$ suspension. Structure and property of the composite were investigated. The results showed that the composite has a porous and uniform structure. Nickel was dispersed in grain boundary and cavity in the form of fine particles. Oxidation of nickel would induce high room--temperature resisitivity and spoil PTC effect. It can be avoided by protection of graphite during sintering. The sintered composite has a very low room--temperature resistivity and little PTC effect. With the absorption of oxygen in grain boundary, PTC effect of the Ni/BaTiO$_{3}$ composite can be effectively renewed by heat--treatment in air. The porose structure and the fine dispersal of nickel were in favor of the renewing of PTC effect.
%K composite
%K positive temperature coefficient
%K barium titanate
%K low resistivity<br>复合材料
%K 正温度系数
%K 钛酸钡
%K 低电阻率
%K 陶瓷复合材料
%K 制备和性能
%K properties
%K Preparation
%K 多孔性结构
%K 复合材料结构
%K 恢复
%K 吸附
%K 处理过程
%K 金属颗粒
%K 方法
%K 石墨
%K 消极影响
%K 效应
%K 室温电阻率
%K 氧化
%K 晶界
%K 分布
%K 分散性
%K 表征
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=5B3AB970F71A803DEACDC0559115BFCF0A068CD97DD29835&cid=84529CA2B2E519AC&jid=C101C4C04993B4D94FCD8446E6CBEB3B&aid=1EA131AE064FA8AA&yid=D0E58B75BFD8E51C&vid=13553B2D12F347E8&iid=B31275AF3241DB2D&sid=BBA8B1249CDAA6CE&eid=36C49E1242CC2C7A&journal_id=1005-3093&journal_name=材料研究学报&referenced_num=0&reference_num=14