Magnetic properties and giant magnetoresistance effect of nanometer Fe-In_2O_3 granular films  

作　　者：ZHANG Lin, LIU Yihua & HUANG BaoxinInstitute of Physics and Microelectronics, Shandong University, Ji’nan 250100, China 

出　　处：《Chinese Science Bulletin》2002年第24期2025-2028,共4页

基　　金：This work was supported by the National Natural Science Foundation of China (Grant No. 59981004).

摘　　要：Nanometer ferromagnetic metal-semiconductor matrix Fe-In2O3 granular films are fabricated by the radio frequency sputtering. Magnetic properties and the giant magnetoresistance (GMR) effect of Fex(In2O3)1-x granular film samples are studied. The result shows that the magnetoresistance (MR) ratio value of the granular film samples with Fe volume fraction x = 35% is 4.5% at room temperature. The temperature dependence (r = 1.5-300 K) of the MR ratio value of Fe0.35(In2O3)0.65 granular films shows that value below 10 K increases rapidly with the decrease of the temperature, and when T = 2 K, value is 85%. Through the study of the dependence of low field susceptibility on temperature and the hysteresis loops at different temperatures, it has been found that, when the temperature decreases to a critical point TP = 10 K, the change of the structure in Fe0.35(In2O3)0.65 granular films results in the transformation of state from ferromagnetic to spin-glass-like. The remarkable increase of the MR ratio valueNanometer ferromagnetic metal-semiconductor matrix Fe-In2O3 granular films are fabricated by the radio frequency sputtering. Magnetic properties and the giant magnetoresistance (GMR) effect of Fex(In2O3)1-x granular film samples are studied. The result shows that the magnetoresistance (MR) ratio value of the granular film samples with Fe volume fraction x= 35% is 4.5% at room temperature. The temperature dependence (r = 1.5-300 K) of the MR ratio value of Fe0.35(In2O3)0.65 granular films shows that value below 10 K increases rapidly with the decrease of the temperature, and when T = 2 K, value is 85%. Through the study of the dependence of low field susceptibility on temperature and the hysteresis loops at different temperatures, it has been found that, when the temperature decreases to a critical point TP = 10 K, the change of the structure in Fe0.35(In2O3)0.65 granular films results in the transformation of state from ferromagnetic to spin-glass-like. The remarkable increase of the MR ratio value of Fe0.35(In2O3)0.65 granular films below 10 K seems to arise from the peculiar conducting mechanism of the granular film samples in the spin-glass-like state.

关 键 词：GRANULAR films magnetic property giant MAGNETORESISTANCE effect structure superparamagnetic. 

分 类 号：O484.43[理学—固体物理]