X-ray absorption near-edge structure and valence state of Mn in (Ga,Mn)N
X-ray absorption near-edge structure and valence state of Mn in (Ga,Mn)N
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DOI：
10.1103/physrevb.72.115209
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发表时间：
2005-09
影响因子：
3.7
通讯作者：
A. Titov;X. Biquard;D. Halley;S. Kuroda;E. Bellet-Amalric;H. Mariette;J. Cibert;A. Merad;G. Merad;M. Kanoun;E. Kulatov;Y. Uspenskiǐ
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文献类型：
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作者：
A. Titov;X. Biquard;D. Halley;S. Kuroda;E. Bellet-Amalric;H. Mariette;J. Cibert;A. Merad;G. Merad;M. Kanoun;E. Kulatov;Y. Uspenskiǐ
用线性缀加平面波方法计算了稀磁半导体（Ga，Mn）N的能带结构和Mn K边的X射线吸收近边结构（XANES）。计算的K边谱与实验数据拟合良好的Ga 1-xMnxN样品与宽范围的Mn含量，从x=0.3%至5.7%。这些样品通过分子束外延生长。X射线衍射测量和扩展的X射线吸收精细结构的研究被用来确认样品的纤锌矿结构，没有任何第二相，和在GaN的镓亚晶格中的Mn的替代位置。测量的XANES光谱的形状不依赖于Mn含量，这意味着在所有样品中Mn原子周围的相同的价态和局部原子结构。测量的光谱和从头计算的结果之间的比较提供了一个清晰的解释的preedge结构：它主要是由于偶极跃迁，与一个单一的峰的情况下，Mn 2+和一个额外的峰Mn 3+。Mn ~（2+）的这种XANES前沿行为在Ga、MnAs和Zn、MnTe上得到了实验证实。我们得出结论，在纤锌矿（Ga，Mn）N中的Mn的价态是3+，这一结论也支持在相同的样品上获得的红外光学透射和磁化数据。
The band structure of the diluted magnetic semiconductor (Ga,Mn)N, and the x-ray absorption near-edge structure (XANES) at the K edge of Mn, were calculated using the linearized augmented plane wave method. The calculated K-edge spectra fit well with experimental data obtained on samples of Ga1-xMnxN with a wide range of Mn content, from x=0.3% to 5.7%. These samples were grown by molecular beam epitaxy. X-ray diffraction measurements and extended x-ray absorption fine structure studies were used to confirm the wurtzite structure of the samples, the absence of any secondary phase, and the substitutional position of Mn in the gallium sublattice of GaN. The shape of the measured XANES spectra does not depend on the Mn content, implying the same valence state and local atomic structure around the Mn atom in all samples. The comparison between the measured spectra and the results of the ab initio calculation offers a clear interpretation of the preedge structure: It is mainly due to dipolar transitions, with a single peak in the case of Mn2+ and an additional peak for Mn3+. Such a behavior of the XANES preedge of Mn2+ was confirmed experimentally on Ga,MnAs and Zn,MnTe. We conclude that the valence state of Mn in wurtzite (Ga,Mn)N is 3+, a conclusion which is also supported by infrared optical transmission and magnetization data obtained on the same samples.