| | | | | 高压烧结的BaTiO_3陶瓷的介电性能 | | | 肖长江;王春华;靳常青;王晓慧 | | | 用两种高压法烧结得到致密的细晶BaTiO3陶瓷。由压力辅助烧结得到的陶瓷晶粒没有过分长大,晶粒尺寸保持在纳米尺度内;用高压成型常压烧结法得到的陶瓷晶粒明显长大。当BaTiO3陶瓷的晶粒尺寸从400 nm减小到50 nm时,相应的介电常数从3 000减小到1 900。介电常数的减小可由晶粒尺寸的减小而导致四方度的降低和非铁电低介电常数的晶界层解释。且铁电-顺电转变由一个尖锐峰变成一个宽的区域,宽的转变区域表现出扩散相变的特征。
【作者单位】：河南工业大学材料科学与工程学院;河南工业大学材料科学与工程学院;中国科学院物理研究所;清华大学材料科学与工程系新型陶瓷和精细工艺国家重点实验室 河南郑州450007;中国科学院物理研究所北京100080;河南郑州450007;北京100080;北京100084
【关键词】：BaTiO3陶瓷;高压;介电性能;扩散相变
【基金】：国家科技部重点基础研究发展计划(“九七三”计划)资助项目(2002CB613301)
【分类号】：TF124.5
【DOI】：CNKI:SUN:YDSG.0.2008-04-024
【正文快照】：
BaTiO3是一种广为人知的铁电材料,在室温时有高介电常数和低损耗,被广泛应用于电子工业中,特别是多层陶瓷电容器(MLCC)中。BaTiO3的介电性能与其微观结构有关。随着晶粒尺寸的减小,介电常数增加;当晶粒尺寸约为1μm,其相对介电常数rε有一个最大值(rε≈5 000)[1];当进一步减小 | | |
| | |  推荐 CAJ下载  PDF下载 | | | CAJViewer7.0阅读器支持所有CNKI文件格式，AdobeReader仅支持PDF格式 | | | | Dielectric Properties of BaTiO_3 Ceramics Sintered by High-pressure Approaches | | | XIAO Chang-jiang1;2;WANG Chun-hua1;JIN Chang-qing2;WANG Xiao-hui3 (1.Dept.of Material Science and Engineering;Henan University of Technology;Zhenzhou 450007;China;2.Institute of Physics;Chinese Academy of Science;Beijing 100080;China;3.State Key Lab.of New Ceramics and Fine Processing;Dept.of Material Science and Engineering;Tsinghua University;Beijing 100084;China) | | | Dense BaTiO3 ceramics were prepared using two high-pressure approaches.The grains did not excessively grow sintering by the high-pressure assisted sintering,and the grains still retained in the range of nanometer size.The sintering temperature obviously decreased when the raw powders were consolidated under high pressure and then sintered at ambient pressure.With grain size reducing from 400 nm to 50 nm,the dielectric constant decreased from 3 000 to 1 900,which could be explained by the tetragonality decreasing and the existence of a low-permittivity,nonferroelectric grain boundary layer in dense BaTiO3 ceramics.In addition,with reducing the grain size,the character of the ferroelectric-paraelectric phase transition transformed from a sharp peak to abroad area.The broad areas exhibited the characteristic of diffuse phase transitions at the transition regions.
【Keyword】：BaTiO3 ceramics;high-pressure;dielectric properties;diffuse phase transition |
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