The electronic structure of a weakly correlated antiferromagnetic metal, SrCrO3: first-principles calculations
The electronic structure of a weakly correlated antiferromagnetic metal, SrCrO3: first-principles calculations
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DOI：
10.1088/1367-2630/13/5/053002
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发表时间：
2010-07
影响因子：
3.3
通讯作者：
Y. Qian;Guangtao Wang;Zhi Li;C. Jin;Z. Fang
中科院分区：
文献类型：
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作者：
Y. Qian;Guangtao Wang;Zhi Li;C. Jin;Z. Fang
基于我们的度调制思想，通过系统的第一性原理计算，我们研究了SrCrO3的电子结构和磁性能。我们的研究结果表明，SrCrO3是一种弱相关反铁磁（AF）金属，这在过渡金属氧化物中是非常罕见的。在各种可能的AF态中，具有少量轨道极化（dxy轨道比dyz/zx轨道占用更多）的c型自旋有序态更受青睐。基于流动Stoner不稳定性和超交换的竞争，我们分析了c型AF态稳定的机理，我们的研究结果表明，磁不稳定性而不是晶格或电荷不稳定性在该体系中起重要作用。实验观察到的c轴压缩四边形畸变可以用c型AF态来解释。利用LDA+U方法对该系统进行了研究，结果表明，如果U较大，则会得到错误的基态。
On the basis of our idea of degree modulation, by using systematic first-principles calculations, we study the electronic structure and magnetic properties of SrCrO3. Our results suggest that SrCrO3 is a weakly correlated antiferromagnetic (AF) metal, a very rare situation in transition-metal oxides. Among various possible AF states, C-type spin ordering with a small amount of orbital polarization (the dxy orbital is more occupied than the dyz/zx orbital) is favored. The detailed understanding of the mechanism that stabilizes the C-type AF state is analyzed on the basis of the competition between itinerant Stoner instability and superexchange, and our results suggest that magnetic instability rather than lattice or charge instabilities plays an important role in this system. The experimentally observed c-axis compressed tetragonal distortion can be naturally explained with the C-type AF state. By using the LDA+U method to study this system, we show that the wrong ground state will be obtained if U is large.