中国物理B ›› 2004, Vol. 13 ›› Issue (9): 1553-1559.doi: 10.1088/1009-1963/13/9/033
路庆凤1, 魏红祥2, 赵素芬3, 张谢群3, 丰家峰3, 韩秀峰3
Wei Hong-Xiang (魏红祥)ab, Lu Qing-Feng (路庆凤)a, Zhao Su-Fen (赵素芬)b, Zhang Xie-Qun (张谢群)b, Feng Jia-Feng (丰家峰)b, Han Xiu-Feng (韩秀峰)b
摘要: Microfabrication and the magneto-transport characteristics of the magnetic tunnel junctions (MTJs) with a spin-valve-type structure of Ta (5nm)/Ni_{79}Fe_{21} (25nm)/Ir_{22}Mn_{78} (12nm)/Co_{75}Fe_{25} (4nm)/Al(0.8nm) oxide/Co_{75}Fe_{25} (4nm)/Ni_{79}Fe_{21} (20nm)/Ta(5nm) were investigated in this paper. A series of experimental data measured with a MTJ was used to verify a magnon-assisted tunnelling model and theory. Furthermore, a micromagnetics simulation shows that the butterfly-like vortex domain structures can be formed under a current-induced Oersted field, which decreases the net magnetization values of the ferromagnetic electrodes under a large dc current (i.e., in high voltage regimes). It is one of the main reasons for the tunnel magnetoresistance ratios to decrease significantly at high voltage biasing.
中图分类号: (Metals and alloys)