摘要
La0.67Sr0.33MnO3/SrFe12O19复合体系的磁滞回线形状特征以及体系的剩磁增强,表明La0.67Sr0.33MnO3与SrFe12O19两相之间存在铁磁交换耦合作用.随SrFe12O19复合量的增加,体系的电阻率增大、低场磁电阻减小,并且出现了金属-半导体的转变,该转变温度低于La0.67Sr0.33MnO3的居里温度.
The magnetic and electric properties and magnetoresistance of the nanocomposites La0.67Sr0.33MnO3/SrFe12O19 were investigated. The exchange coupling must exist between La0.67Sr0.33MnO3Sr and Fe12O19 according to the characteristic of the hysteresis loop and the effect of remanence enhancement of composites. We observe the resistivity of the samples is greater than without SrFe12O19 addition and a meltal-insulator transition peak in the resistance can be observed and the transitional temperature is lower than the Courier temperature of La0.67Sr0.33MnO3. Meanwhile, we observe a decrease of the low-field magnetoresistance with content of SrFe12 O19 increase. According to theoretical research, it is found that the decreasing of the low-field magnetoresistance is caused by the ferromagnetic exchange coupling.
出处
《材料研究与应用》
CAS
2007年第2期103-107,共5页
Materials Research and Application
关键词
纳米复合体系
电性
磁性
磁电阻
交换耦合
nanocomposite
electric properties
magnetic properties
magnetoresistance
exchange coupling
