Pressure-induced spin-state and insulator-metal transitions in Sr3Fe2O5 from first principles
Pressure-induced spin-state and insulator-metal transitions in Sr3Fe2O5 from first principles
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DOI：
10.1209/0295-5075/102/67004
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发表时间：
2013-06
期刊：
影响因子：
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通讯作者：
T. Jia;Hua-Yao Wu;Xiaoli Zhang;Ting Liu;Z. Zeng;H. Lin
中科院分区：
文献类型：
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作者：
T. Jia;Hua-Yao Wu;Xiaoli Zhang;Ting Liu;Z. Zeng;H. Lin
采用混合泛函方法计算发现，在36.7GPa的实验压力下，层状Sr 3Fe 2 O 5发生了从高自旋到中自旋的自旋态转变（SST）.这种跃迁是由最高晶场能级x2-y2的电子耗尽触发的。另一方面，减少的层间距离提升了反键3 z2 − r2态，因此它的电子占据部分转移到未被占据的x2 − y2导带。这导致绝缘体-金属过渡（IMT）。我们注意到IMT与SST密切相关，但它们有不同的起源。
Using hybrid functional calculations, we find that under the experimental pressure of 36.7 GPa, layered Sr3Fe2O5 undergoes a spin-state transition (SST) from high spin to intermediate spin. This transition is triggered by an electron depletion of the highest crystal-field level x2 − y2. On the other hand, a reduced inter-layer distance lifts up the antibonding 3z2 − r2 state, and thus its electron occupation is partially shifted to the otherwise unoccupied x2 − y2 conduction band. This gives rise to an insulator-metal transition (IMT). We note that the IMT is closely related to the SST, but they somewhat have a different origin.