烧结工艺对La_(0.67)Ca_(0.33)MnO_3多晶物理性质的影响  

Effect of Sintering Process on the Physical Properties of La_(0. 67)Ca_(0. 33)MnO_3 Polycrystal

作　　者：蔡云麒[1] 马吉[1] 张辉[1] 王文章[1] 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》2013年第9期1853-1856,1863,共5页Journal of Synthetic Crystals

基　　金：国家自然科学基金(50902062)

摘　　要：利用溶胶-凝胶法成功制备了La0.67Ca0.33MnO3粉末,并通过优化烧结工艺获得了物理性能优异的La0.67Ca0.33MnO3多晶靶材。利用X射线衍射仪和扫描电子显微镜分别测试了样品的物相、结构和微观形貌,并利用四探针法测试了靶材的电阻率-温度曲线。结果表明,影响TCR的主要因素有晶粒的化学均匀性、晶粒尺寸和晶界的数量,样品具有接近室温的金属-绝缘转变温度(T MI=274 K)和高的电阻温度系数(TCR=13.5%)。La0.67Ca0.33MnO3 powder was successfully prepared by sol-gel method, and La0.67Ca0.33 MnO3 polycrystal target with excellent physical properties have been acquired by optimizing the sintering process. The crystalline structure of the samples was examined by the X-ray diffraction. The grain sizes and morphologies of the targets were examined under scanning electron microscope. The resistivity versus temperature （p-T） relationship was measured using the standard four-probe method. The results show that the main factors affecting the TCR are chemical uniformity, grain size, and the proportion of grain boundary, and the samples have the metal-insulation transformation near room temperature （TMI= 274 K） and the high temperature coefficient of resistance （ TCR = 13.5% ）.

关 键 词：LA0 67Ca0 33MnO3 多晶 TCR 溶胶-凝胶 

分 类 号：TB34[一般工业技术—材料科学与工程]