基于XPS与XAS的稀磁半导体GaMnN电子结构研究.

Study on electronic structure of dilute magnetic semiconductor GaMnN based on XPS and XAS.

This paper is based on the X-ray photoelectron spectroscopy (XPS and X-ray absorption spectroscopy (XAS with the synchrotron radiation technology. It aims to test the electronic structures of dilute magnetic semiconductor GaMnN films with different Mn doping concentrations prepared by metal organic chemical vapor deposition technology (MOCVD, to explore the influences of Mn doping concentration on the local environment and electronic states of the magnetic atom Mn, and hence to expose the mechanism for the change of material ferromagnetism. The XPS and XAS data analysis show that Mn2+ and Mn3+ coexist in the film samples, the proportion of Mn2+ in sample D is as high as 70%-80%; the N vacancy increases with the increase of Mn doping concentration and it can reduce the hole concentration, as a result, the exchange interaction between Mn 3d and N 2p orbitals is reduced, which weakens the ferromagnetism of the system. In addition, Mn doping concentration also affects the strength of the p-d coupling hybridization ability of GaMnN films. When the Mn doping concentration is 0.018, the system has a strong p-d coupling hybridization ability. [ABSTRACT FROM AUTHOR]

采用基于同步輻射技術的X射線光電子能譜（XPS）與X射線吸收譜（XAS）測試由金屬有機化學氣相沉積（MOCVD）技術制備的不同Mn摻雜濃度的稀磁半導體GaMnN薄膜的電子結構，探究Mn摻雜濃度對磁性原子Mn周圍的局域環境和電子態等方面的影響，并闡述材料鐵磁性變化的機理. XPS和XAS圖譜分析表明：Mn2+和Mn3+共存于薄膜樣品內，樣品D中Mn2+占比高達70%-80%,N空位隨Mn摻雜濃度增加而增多且N空位能夠使空穴濃度降低，導致Mn 3d和N 2p軌道間的相互交換作用減小，從而減弱體系鐵磁性.此外，Mn不同的摻雜濃度會影響GaMnN薄膜p-d耦合雜化能力的強弱，當摻Mn 1.8%時具有較強的p-d耦合雜化能力.  [ABSTRACT FROM AUTHOR]

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