Structure and Transport Behaviors of Nanograin La_(0.8)Sr_(0.2)Mn_(1-x)Al_xO_3  

作　　者：江少群 马欣新 孙明仁 唐光泽 王刚 

机构地区：[1]School of Materials Science and Engineering, Harbin Institute of Technology

出　　处：《Journal of Rare Earths》2007年第S2期45-49,共5页稀土学报（英文版）

基　　金：Project supported bythe Programfor New Century Excellent Talents in University

摘　　要：The influence of aluminum doping at Mn-site in nanograin compound La0.8Sr0.2MnO3 was investigated based on X-ray diffraction, scanning electron microscope and resistivity measurement, in the light of structure and transport properties. The results showed that Al doping was favorable to the globurizing of powders and grain size uniformity, however, depressed the particles growth. The resistivity of system increased rapidly and the metal-insulator transition temperature (TIM) and room temperature magnetoresistance decreased as the aluminum concentration increased. In the T>TIM region, the current carriers were moving in variable range transition mode. The resistivity of La0.8Sr0.2Mn1-xAlxO3 for x=0.05 and 0.1 satisfied metal model in the T<TIM region. The characteristics of the transport behavior for aluminum doping were analyzed in terms of destroying the double exchange channel of Mn3+-O-Mn4+, distortion of the cell lattice and change of powder particles size and shape.The influence of aluminum doping at Mn-site in nanograin compound La0.8Sr0.2MnO3 was investigated based on X-ray diffraction, scanning electron microscope and resistivity measurement, in the light of structure and transport properties. The results showed that Al doping was favorable to the globurizing of powders and grain size uniformity, however, depressed the particles growth. The resistivity of system increased rapidly and the metal-insulator transition temperature (TIM) and room temperature magnetoresistance decreased as the aluminum concentration increased. In the T>TIM region, the current carriers were moving in variable range transition mode. The resistivity of La0.8Sr0.2Mn1-xAlxO3 for x=0.05 and 0.1 satisfied metal model in the T<TIM region. The characteristics of the transport behavior for aluminum doping were analyzed in terms of destroying the double exchange channel of Mn3+-O-Mn4+, distortion of the cell lattice and change of powder particles size and shape.

关 键 词：MAGNETORESISTANCE metal-insulator transition exchange interactions transport property rare earths 

分 类 号：O474[理学—半导体物理]