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arXiv 0904.4791cond-mat.mtrl-sci
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Mg(x)Zn(1-x)O合金结构相变和基本带隙的第一性原理研究

Structural phase transitions and fundamental band gaps of Mg(x)Zn(1-x)O alloys from first principles

I. V. Maznichenko, A. Ernst, M. Bouhassoune, J. Henk, M. Daene, M. Lueders, P. Bruno, W. Hergert, I. Mertig, Z. Szotek, W. M. Temmerman

摘要:

采用多重散射理论方法(Korringa-Kohn-Rostoker方法),通过详细的第一性原理计算,研究了Mg(x)Zn(1-x)O合金的结构相变和基本带隙.无序合金的相干势近似(CPA)内处理。对各种晶相的计算得到的相图与实验和其它理论方法符合得很好。预测了在Mg浓度x = 0.33时,从纤锌矿结构到岩盐结构的相变,这与实验值0.33 - 0.40接近。的基本带隙的大小,通常被低估的局部密度近似,是相当大的改善自相互作用校正。ZnO与Mg合金化后间隙的增加证实了实验趋势。我们的研究结果是相关的应用在光学,电气,特别是在磁电器件。

英文摘要:

The structural phase transitions and the fundamental band gaps of Mg(x)Zn(1-x)O alloys are investigated by detailed first-principles calculations in the entire range of Mg concentrations x, applying a multiple-scattering theoretical approach (Korringa-Kohn-Rostoker method). Disordered alloys are treated within the coherent potential approximation (CPA). The calculations for various crystal phases have given rise to a phase diagram in good agreement with experiments and other theoretical approaches. The phase transition from the wurtzite to the rock-salt structure is predicted at the Mg concentration of x = 0.33, which is close to the experimental value of 0.33 - 0.40. The size of the fundamental band gap, typically underestimated by the local density approximation, is considerably improved by the self-interaction correction. The increase of the gap upon alloying ZnO with Mg corroborates experimental trends. Our findings are relevant for applications in optical, electrical, and in particular in magnetoelectric devices.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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