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arXiv · 1605.06358

Elementary specific spin and orbital moments of ultrathin CoFeB amorphous films on GaAs(100)

Yu Yan·Cong Lu·Hongqing Tu·Xianyang Lu·Wenqing Liu·Junlin Wang·Iain Will·Balati Kuerbanjiang·Vlado K. Lazarov·Jing Wu·Johnny Wong·Biao You·Jun Du·Rong Zhang·Yongbing Xu
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Abstract

Nanoscale CoFeB amorphous films have been synthesized on GaAs(100) and studied with X-ray magnetic circular dichroism (XMCD) and transmission electron microscopy (TEM). We have found that the ratios of the orbital to spin magnetic moments of both the Co and Fe in the ultrathin amorphous film have been enhanced by more than 300% compared with those of the bulk crystalline Co and Fe, and in specifically, a large orbital moment of 0.56*10^-6 B from the Co atoms has been observed and at the same time the spin moment of the Co atoms remains comparable to that of the bulk hcp Co. The results indicate that the large uniaxial magnetic anisotropy (UMA) observed in the ultrathin CoFeB film on GaAs(100) is related to the enhanced spin-orbital coupling of the Co atoms in the CoFeB. This work offers experimental evidences of the correlation between the UMA and the elementary specific spin and orbital moments in the CoFeB amorphous film on the GaAs(100) substrate, which is significant for spintronics applications.

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Yu Yan, Cong Lu, Hongqing Tu, Xianyang Lu, Wenqing Liu, Junlin Wang, Iain Will, Balati Kuerbanjiang, Vlado K. Lazarov, Jing Wu, Johnny Wong, Biao You, Jun Du, Rong Zhang, Yongbing Xu. 2016-05-20. Elementary specific spin and orbital moments of ultrathin CoFeB amorphous films on GaAs(100). https://doi.org/10.1063/1.4962994

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