Mn/GaAs(100)界面电子结构的同步辐射光电子能谱研究

ELECTRONIC STRUCTURE OF Mn/GaAs(100) STUDIEDBY SPECTRA OF ELECTRON PHOTOEMISSIONWITH SYNCHROTRON RADIATION

利用同步辐射光电子能谱,研究了室温下在GaAs(100)表面上淀积的Mn的超薄膜的电子结构.实验发现,在θ<2ML的覆盖度下,Mn3d电子的能量态密度分布与体金属α-Mn差别很大;当θ>2ML之后,便逐步接近α-Mn的体电子结构.这一结果可由Mn3d电子的自旋向上带和自旋向下带的交换分裂很好地解释.由此推断,当覆盖度θ<2ML时,在GaAs(100)表面上淀积的Mn的超薄膜具有磁有序结构.

The electronic structure of the ultra-thin Mn overlayer on GaAs(100) is studied by spectra of electron photoemission with synchrotron radiation. It is found that the valence band spectra of the Mn overlayer at θ<2ML are quite different from that of bulk α-Mn. The similarity between them starts to show up as θ>2ML. The results can be well explained by the exchange splitting between the spin up and spin down bands of the Mn3d electrons. It is concluded that the magnetic ordering is established in the ultra thin Mn overlayer on GaAs(100) at θ<2ML.