Effects of dwell time during sintering on electrical properties of 0.98(K_(0.5)Na_(0.5))NbO_3-0.02LaFeO_3 ceramics  

保温时间对0.98(K_(0.5)Na_(0.5))NbO_3-0.02LaFeO_3陶瓷电性能的影响(英文)

作　　者：程花蕾[1] 周万城[1] 杜红亮[1] 罗发[1] 朱冬梅[1] 

机构地区：[1]西北工业大学材料科学与工程学院,凝固技术国家重点实验室,西安710072

出　　处：《Transactions of Nonferrous Metals Society of China》2013年第10期2984-2988,共5页中国有色金属学报（英文版）

基　　金：Project(CX201108)supported by the Doctorate Foundation of Northwestern Polytechnical University,China;Project(51072165)supported by the National Natural Science Foundation of China;Projects(KP200901,SKLSP201104)supported by the Fund of State Key Laboratory of Solidification Processing in NWPU,China

摘　　要：The effects of dwell time on the phase structure, microstructure, and electrical properties were investigated for the 0.98（K0.sNa0.5）NbO3-0.02LaFeO3 ceramics （abbreviated as 0.98KNN-0.02LF）. All the ceramics sintered for different dwell time are of pure phase and the peak intensity of the 0.98KNN-0.02LF ceramics becomes stronger with a longer dwell time. Denser microstructures with larger grain size are developed for the sample with a longer dwell time. The maximum dielectric permittivity decreases with increasing the dwell time, and the deteriorative dielectric properties are due to the increasing grain size and the domain wall motion. Ferroelectric properties results indicate that 2Pr value slightly decreases with increasing the dwell time, while the 2Ec value increases. Consequently, the 0.98KNN-0.02LF ceramic sintered at 1150 ℃ for 2 h shows optimum dielectric properties （er=2253 and tan fi〈5%） and ferroelectric properties （2Pr=34.51 gC/cm2 and 2Ec=5.07 kV/mm）.研究保温时间对0.98(K0.5Na0.5)NbO3-0.02LaFeO3(缩写为0.98KNN-0.02LF)无铅陶瓷相结构、显微组织、介电性能及铁电性能的影响。所有烧结样品均为纯的伪立方钙钛矿相,保温时间对相结构影响不大。随着保温时间的延长,样品的XRD衍射峰逐渐增强,并且向低角度移动。SEM观察结果显示,随着保温时间的延长,陶瓷样品的致密性提高,晶粒异常长大并出现孪晶结构。介电温谱表明,随着保温时间的延长,介电性能有所降低。电滞回线结果表明,2P r随着保温时间的延长而增大的程度有所减小,而2E c略有增加。在1150°C烧结2 h得的到陶瓷的性能较优:εr=2253,tanδ<5%,2P r=34.51μC/cm2,2E c=5.07 kV/mm。

关 键 词：(K0.5Na0.5)NbO3 dwell time dielectric properties ferroelectric property lead-free ceramics 

分 类 号：TQ174.1[化学工程—陶瓷工业]