烧结工艺对Sr_(0.3)Ba_(0.7)Bi_(3.7)La_(0.3)Ti_4O_(15)陶瓷显微结构及介电性能的影响  

Effect of Sintering Process on the Microstructure and Dielectric Properties of Sr_(0.3)Ba_(0.7)Bi_(3.7)La_(0.3)Ti_4O_(15) Ceramics

作　　者：何新华[1] 郑敏贵[1] 陈志武[1] 

机构地区：[1]华南理工大学,广东广州510640

出　　处：《稀有金属材料与工程》2009年第A01期424-427,共4页Rare Metal Materials and Engineering

基　　金：广东省自然科学基金(000536)

摘　　要：采用传统高温直接烧结和低温保温的两步烧结工艺制备铋层结构铁电陶瓷Sr0.3Ba0.7Bi3.7La0.3Ti4O15,获得结构致密、均匀、粒径介于1～3μm的陶瓷材料。结合XRD和SEM分析研究烧结工艺对陶瓷的晶相、显微结构和介电性能的影响。研究表明:采用两步烧结法使铋挥发和氧空位浓度降低,从而显著减弱了陶瓷的高温低频耗散。随着保温时间的增加,晶格畸变减少,居里温度降低了60℃左右。高温绝缘性也得到明显改善,高温电导率随保温时间的增加显著降低,保温15h所得陶瓷样品的电导率降低了一个数量级,在280℃时为5.2×10-9S·m-1。Bismuth layer structured ferroelectric ceramics Sr0.3Ba0.7Bi3.7La0.3Ti4O15 were fabricated by different sintering programs including conventional sintering （dwelling at maximum temperature） and two-step sintering （dwelling at lower temperature）. The effect of sintering process on crystalline phase, microstructures and dielectric properties of Sr0.3Ba0.7Bi3.7La0.3Ti4O15 ceramics was investigated by means of XRD and SEM. Dense and uniform ceramic materials with grain size of 1-3 μm were obtained. The decrease in Bismuth volatilization and oxygen vacancy, resulting from two-step sintering, reduces low frequency dispersion at higher temperature. Crystal distortion decreases with increasing dwelling time, and the Curie temperature is lowered by approx. 60 ℃. The conductivity at higher temperature decreases with increasing dwelling time. The conductivity of ceramic specimens with a dwelling time of 15 h reduces one order of magnitude, and the conductivity at 280 ℃ is 5.2×10^-9 S·m^-1.

关 键 词：铋层结构铁电材料 两步烧结 居里温度 介电性能 

分 类 号：TQ174.1[化学工程—陶瓷工业]