Effective way to improve the magnetoresistance effect in perovskite at room temperature
The magnetic and electrical properties of the La0.67Ca0.25Sr0.08MnO3/xAg composite system are systematically investigated as a function of Ag-added content. With increasing the Ag dopant amount, the magnetization decreases a little while Curie temperature (TC) is almost independent of Ag content around 312 K. The resistivity reduces rapidly with Ag addition (x < 0.25) due to the decomposed metal Ag, and then it increases slightly which is probably induced by the less Ag content related to the volatilization of Ag during calcinations. At low temperature, the ρ - T curves fit well by the expression of ρ=ρ 0+ρ 2T 2+ρ 4.5T 4.5 while all data for the above TC can be fitted by using the adiabatic small-polaron-hopping model ρ=ρ 0T exp(E/kBT). The enhancement of MR effect (41%) at room temperature is mainly related to the coexistence of intrinsic MR properties and the spin dependent scattering of conduction electrons at the interfaces. These results indicate that combining the doping effect with the composite method is an effective selection in enhancement of MR at room temperature, which is very meaningful for the application research.
Huang Baoxin Li Jian Wang Junhua Chen Kezheng Liu Yihua Mei Liangmo
Department of Materials Science and Engineering, Qingdao University of Science & Technology, Qingdao Department of Physics, Weifang University, Weifang, 261061 China Department of Materials Science and Engineering, Qingdao University of Science & Technology, Qingdao Institute of Physics and Microelectronics and State Key laboratory of Crystal Materials, Shandong Un
国际会议
桂林
英文
1-8
2010-11-16（万方平台首次上网日期，不代表论文的发表时间）