Structure and Transport Behaviors of Nanograin La0.8Sr0.2Mn1-xAlxO3
来源期刊:JOURNAL OF RARE EARTHS2007年增刊第1期
论文作者:Sun Mingren Jiang Shaoqun Wang Gang Tang Guangze Ma Xinxin
Key words:magnetoresistance; metal-insulator transition; exchange interactions; transport property; rare earths;
Abstract: 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 TTIM 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 TTIM 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.
Sun Mingren1,Jiang Shaoqun1,Wang Gang1,Tang Guangze1,Ma Xinxin1
(1.School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China)
Abstract: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 TTIM 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 TTIM 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.
Key words:magnetoresistance; metal-insulator transition; exchange interactions; transport property; rare earths;
【全文内容正在添加中】