Half-metallic diluted antiferromagnetic semiconductors

半金属稀释反铁磁半导体

• 批准号: 17340095
• 负责人: AKAI Hisazumi
• 金额: $ 3.83万
• 依托单位: Osaka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2005
• 资助国家: 日本
• 起止时间: 2005 至 2007
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-17340095/
• 关键词: computational physics; computational materials design; diluted magnetic semiconductors; full potential KKR; spintronics; half-metals; hyperfine fileds; giant magneto resistance; 希薄磁性半導体; 計算機ナノマテリアルデザイン; フルポテンシャルKKR; グリーン関数法; 計算機マテリアルシミュレーション

On the basis of first-principles electronic structure calculations, we have shown that various compounds semiconductors as well as TiO2, chalchopyrite-type compounds doped with more than two kind of magnetic ions such as Cr-Fe and V-Co may exhibit half-metallic antiferromagnetism. We further have calculated the magnetic transition temperature of them materials using the magnetic coupling constants, which are calculated by the Green's function method, combined with a cluster approximation. The results show that the magnetic transition temperature of some half-metallic antiferromagnetic semiconductors will exceeds the room temperature. We also have developed the computer code that enables us to calculate the DC conductivity of these materials using the Kubo-Greenwood formula. Specifically, we have studies the followings:1) We have designed hetero-structures using II-VI compounds half metallic diluted antiferromagnetic semiconductors It was shown that the electron mattering dues to the existence of a possible anti-phase domain boundary might cause GMR effect.2) We have proposed the method to verify the half-metallic antiferromagnetism. On a of the possibility is XMCD and the other is using NMR technique. We actually calculated K-edge XMCD absorption spectra and the hyperfine interactions of probe nuclei in half-metallic antiferromagnets.

在第一性原理电子结构计算的基础上，我们证明了各种化合物半导体以及掺杂两种以上磁性离子（如Cr-Fe和V-Co）的TiO_2、黄铜矿型化合物都可能表现出半金属反铁磁性。利用绿色函数方法计算的磁耦合常数，结合集团近似，计算了它们的磁转变温度。结果表明，某些半金属反铁磁半导体的磁转变温度将超过室温。我们还开发了计算机代码，使我们能够使用Kubo-Greenwood公式计算这些材料的直流电导率。具体而言，我们研究了以下几个方面：1）设计了II-VI族化合物半金属稀释反铁磁半导体异质结构，证明了由于可能存在的反相畴界而引起的电子物质化可能会引起巨磁电阻效应。2）提出了验证半金属反铁磁性的方法。一种可能性是XMCD，另一种可能性是使用NMR技术。我们实际计算了半金属反铁磁体的K边XMCD吸收谱和探测核的超精细相互作用。

项目成果

Magnetic properties of 3d pyrite-type mixed crystals calculated by the full-potential KKR-CPA method

• DOI: 10.1088/0953-8984/19/36/365215
• 发表时间: 2007-08
• 期刊: Journal of Physics: Condensed Matter
• 作者: M. Ogura;H. Akai

計算機マテリアルデザイン

计算机材料设计

• 发表时间: 2007
• 作者: N. H. Long;M. Ogura and H. Akai;M. Ogura and H. Akai;赤井久純
• 通讯作者: 赤井久純

薄磁性半導体の輸送現象

薄磁性半导体中的输运现象

• 发表时间: 2006
• 作者: 赤井 久純;小倉 昌子
• 通讯作者: 小倉 昌子

Optical conductivity of diluted magnetic semiconductors

稀磁半导体的光导率

• 发表时间: 2005
• 作者: H. Akai;M. Ogura and H. Yonehara
• 通讯作者: M. Ogura and H. Yonehara

反強磁性ハーフメタリック半導体およびその製造方法

反铁磁半金属半导体及其制造方法

• 发表时间: 2005