采用磁控溅射方法制备结构为CoFe/Cu/CoFe/IrMn的自旋阀结构多层膜,研究它的热弛豫现象.实验表明,多层膜在其负饱和场中等待时,钉扎层的磁滞回线向正场方向移动,交换偏置场单调减小,并且随温度升高而加速减小.交换偏置场的减小是由反铁磁层的反转引起的,它可以看作是反铁磁磁矩越过一定能垒的热激活反转过程.温度升高后,能垒的分布发生了改变.
Spin valve mutilayers with structure of CoFe/Cu/CoFe/IrMn was prepared by magnetron sputtering method and their thermal relaxation was studied. Results show that when holding in the negative saturation field, the hysteresis loop of the pinned ferromagnetic layer shifts towards the zero field and exchange bias field H_(ex) decreases monotonously, whose decay is enhanced by the temperature increasing. The decay is resulted from reversal of the antiferromagnetic layer, which can be considered as thermal activation reversal process of antiferromagnetic moment over some energy barrier; the distribution of the energy barrier changes in some way as the temperature increases.
参考文献
| [1] | Meiklejohn W H;Bean C P .[J].Physical Review,1956,102(05):1413. |
| [2] | Meiklejohn W H;Bean C P .[J].Physical Review,1957,105(03):904. |
| [3] | Fontana R E;McDonald S A;Santini H A et al.[J].IEEE Transactions on Magnetics,1999,35(02):806. |
| [4] | You C Y;Goripati H S;Furubayashi T et al.[J].Applied Physics Letters,2008,93(01):12 501. |
| [5] | Thomas L.;Negulescu B. .Metastable antiferromagnetic domain configurations in exchange biased bilayers[J].Journal of Applied Physics,2003(10 Pt.3):8606-8608. |
| [6] | Abnormal temperature dependence of exchange bias in the NiFe5/Ta0.2/IrMn8 system[J].Journal of Applied Physics,2003(10):6614-6616. |
| [7] | Nishioka K .[J].Journal of Applied Physics,1999,86(11):6305. |
| [8] | Wang YG.;Petford-Long AK. .Magnetization reversal of the ferromagnetic layer in IrMn/CoFe bilayers[J].Journal of Applied Physics,2002(11):6699-6707. |
| [9] | Vallejo-Fernandez G;Aley N P;Fernandez-Outon L E et al.[J].Journal of Applied Physics,2008,104(03):33 906. |
| [10] | Goodman AM.;O'Grady K.;Owen NW.;Petford-Long AK.;Laidler H. .Magnetic viscosity effects on the pinned layer loop of spin-valve materials[J].Journal of Applied Physics,2000(9 Pt.3):6409-6411. |
| [11] | Hughes T.;O'Grady K.;Laidler H. .Thermal activation of magnetization reversal in spin-valve systems[J].Journal of Applied Physics,2001(10):5585-5591. |
| [12] | Vallejo-Fernandez G;Fernandez-Outon L E;O'Grady K .[J].Journal of Applied Physics,2008,103(07):07C101. |
| [13] | Xi Haiwen;Franzen S;Mao S et al.[J].Physical Review B:Condensed Matter,2007,75(01):14 434. |
| [14] | Czapkiewicz M;Stobiecki T;Dijken S .[J].Physical Review B:Condensed Matter,2008,77(02):24 416. |
| [15] | Carey MJ.;Gurney BA.;Childress JR.;Lin T.;Smith N. .Thermally assisted decay of pinning in polycrystalline exchange biased systems (invited)[J].Journal of Applied Physics,2001(11 Pt.2):6579-6584. |
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