高电阻温度系数的La_(0.67)(Ca_(0.33-x)Sr_x)MnO_3多晶陶瓷制备与电学性能研究  

Preparation and Electrical Properties of La_(0.67)(Ca_(0.33-x)Sr_x)MnO_3 Polycrystalline Ceramics with High Temperature Coefficient of Resistance

作　　者：崔琦[1] 张辉[1] 王文章[1] 张斌[1] 罗均美 陈清明[1] 

机构地区：[1]昆明理工大学材料科学与工程学院,昆明650093

出　　处：《人工晶体学报》2015年第1期122-126,共5页Journal of Synthetic Crystals

基　　金：国家自然科学基金(50902062)

摘　　要：采用溶-凝胶法在1450℃烧结12 h的条件下,制备了x组分为0、0.01、0.03、0.05、0.06、0.07的La0.67(Ca0.33-xSrx)MnO3(LCSMO)多晶陶瓷,通过R-T、XRD和SEM测试分析,结果表明,溶胶-凝胶方法制备的LCSMO多晶陶瓷其物相较纯,阻温特性良好,晶粒尺寸大,致密度高。在未掺Sr时,该体系电阻温度系数(TCR)达到最高值42.5%。随着Sr掺杂比增加,金属-绝缘体转变温度TP升高,TCR降低,而在TP达到室温时,LCSMO多晶陶瓷具有较大的TCR(9%以上)。在LCSMO多晶体系中如此大的TCR较为罕见,使其具有重要的潜在应用价值。The polycrystalline La0. 67（Ca0. 33- xSrx） MnO3（x = 0,0. 01,0. 03,0. 05,0. 06,0. 07）ceramics were prepared by sol-gel method and sintered at 1450 ℃ for 12 h. Properties of the ceramics were characterized by R-T,XRD and SEM measurements. The experimental results show that the LCSMO polycrystalline ceramics prepared by the sol-gel method have pure phase,good resistance-temperature characteristics,large crystal grain size and high density. The maximum temperature coefficient of resistance value is 42. 5% before Sr doped. With the increasing of the Sr concentration,the metalinsulator transition temperature TPincreases,but the TCR decreases when the TPis near to the room temperature. Nevertheless,the TCR of LCSMO ceramics still show large value（greater than 9%）,which is relatively rare in the LCSMO polycrystalline ceramics. This makes it have important potential applications.

关 键 词：La0.67(Ca0.33-xSrx)MnO3 溶胶-凝胶法 电阻温度系数 金属-绝缘体转变 

分 类 号：TB34[一般工业技术—材料科学与工程]