摘要
The influence of Gd doping at La-site on the electrical transport properties and the colossal magnetoresistance of La0.7-xGdxSr0.3MnO3 (x = 0.00, 0.10, 0.15, 0.20, 0.30, 0.40, 0.50, 0.60, and 0.70) is studied. The experimental results indicate that the transport properties exhibit abnormal behavior under high doping condition. For x = 0.50, we find that a transition from metal to insulator occurs after the occurrence of insulator-metal transition near Tc, which seldom occurs in ABO3 structure. For samples x = 0.60 and 0.70, it exhibits insulator behavior far above Tc. These abnormal behaviors are attributed to different magnetic background, i.e. the system undergoes a transition from long range ferromagnetic order to the cluster-spin glass state and further to antiferromagnetic order.
The influence of Gd doping at La-site on the electrical transport properties and the colossal magnetoresistance of La0.7?x Gd x Sr0.3MnO3 (x=0.00, 0.10, 0.15, 0.20, 0.30, 0.40, 0.50, 0.60, and 0.70) is studied. The experimental results indicate that the transport properties exhibit abnormal behavior under high doping condition. Forx=0.50, we find that a transition from metal to insulator occurs after the occurrence of insulator-metal transition nearT c, which seldom occurs in ABO3 structure. For samplesx=0.60 and 0.70, it exhibits insulator behavior far aboveT c. These abnormal behaviors are attributed to different magnetic background, i.e. the system undergoes a transition from long range ferromagnetic order to the cluster-spin glass state and further to antiferromagnetic order.
基金
the National Natural Science Foundation of China(Grant No.19934003)
the Research Fund for the Doctoral Program of Higher Education
关键词
磁性的结构
搬运性质
庞大的磁致电阻效果
magnetic structure
transport properties
colossal magnetoresistance effect
