Fe离子掺杂对La_(0.67)Ca_(0.33)Mn_(1-x)Fe_xO_3体系晶体结构、输运性质的影响  

Effect if Fe Substitution on the Crystal Structure and Transport Properties of Layered Perovskite Manganite La_(0.67)Ca_(0.33)Mn_(1-x)Fe_xO_3

作　　者：魏桂森[1] 徐勇光[1] 张星[2] 常方高[1] 王海英[1] 

机构地区：[1]河南师范大学物理与信息工程学院,河南新乡453007 [2]黔西南民族师范高等专科学校物理系,贵州兴义562400

出　　处：《河南师范大学学报（自然科学版）》2008年第4期60-63,共4页Journal of Henan Normal University(Natural Science Edition)

基　　金：国家自然科学基金(60571063);河南省教育厅自然科学基金(2007140008)

摘　　要：采用固相反应法制备了La0.67Ca0.33Mn1-xFexO3(0 x 0.2)系列样品.实验研究了Fe离子掺杂稀土锰氧化物La0.67Ca0.33MnO3的电输运性质、微观结构和导电机制.结果表明:样品高温下导电遵从Mott变程跳跃机制;相同温度下烧结的样品,体系电阻率急剧增加,绝缘—金属转变温度TIM向低温方向移动.相同Fe替代含量的样品,在1200℃、1250℃、1300℃3个不同烧结温度下,晶格常数c变化不大,晶格常数a、b和晶胞体积随着烧结温度的升高而减小,晶体颗粒和体系电阻率随着烧结温度的升高而增大,绝缘—金属转变温度TIM向高温方向移动.La0. 67 Ca0. 33 Mn1-x FexO3 has been prepared by solid reaction method. The influences of doping Fe on the crystal structure and transport properties of the layered perovskite manganite La0. 67 Ca0.33 Mn1-x FexO3 are investigated. The result indicates that the temperature dependence of resistance follows the formula above the metal-insulator transition temperatures. In the same sinter temperature with increasing of Fe content the crystal lattice and the crystal vol. changes little, while the resistance increases rapidly and the metal-insulator transition tenperature moves to lower temperature. The crystal lattice c of the same Fe content samples prepared by increasing sinter temperature（1 200 ℃ ,1 250 ℃ ,1 300 ℃ ） has no change but the crystal lattice a,b and its vol. decreases, the crystal grain size and resistance increase and the metal-insulator transition temperature moves to higher temperature.

关 键 词：输运性质 Mott变程跳跃 CMR 

分 类 号：TM27[一般工业技术—材料科学与工程]