Structural, electronic and vibrational properties of ultra-thin octahedrally coordinated structure of EuO2
Structural, electronic and vibrational properties of ultra-thin octahedrally coordinated structure of EuO2
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DOI：
10.1016/j.jmmm.2019.165668
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发表时间：
2020-01
影响因子：
2.7
通讯作者：
M. Ozcan;S. Ozen;M. Yagmurcukardes;H. Sahin
中科院分区：
文献类型：
--
作者：
M. Ozcan;S. Ozen;M. Yagmurcukardes;H. Sahin
利用第一性原理计算研究了氧化铕的新型稳定超薄相。总能量计算结果表明，EuO 2和Eu（OH）2的单层结构可以稳定在八面体配位（1 T）的原子结构中。然而，声子计算表明，尽管这两种结构在能量上都是可行的，但只有1 T-EuO 2相具有动力学稳定性。1 T-EuO 2的声子谱显示出三个拉曼激活模：一个非简并的面外A1 g模（353.5 cm-1）和两个双简并的面内Eg模（304.3 cm-1）.磁基态和电子能带色散计算表明，单层EuO 2是一种金属，每个晶胞的净磁矩为5 μ B，表现为半金属亚铁磁行为.此外，EuO 2的半金属亚铁磁特性的鲁棒性被证实的电场和充电的应用。单层1 T-EuO 2具有稳定的超薄结构和半金属亚铁磁特性，是一种具有应用前景的纳米电子和自旋电子学材料。
Novel stable ultra-thin phases of europium oxide are investigated by means of state-of-the-art first principles calculations. Total energy calculations show that single layers of EuO 2 and Eu (OH) 2 can be stabilized in an octahedrally coordinated (1T) atomic structure. However, phonon calculations reveal that although both structures are energetically feasible, only the 1T-EuO 2 phase has dynamical stability. The phonon spectrum of 1T-EuO 2 displays three Raman active modes; a non-degenerate out-of-plane A 1 g mode at 353.5 cm-1 and two doubly-degenerate in-plane E g modes at 304.3 cm-1. Furthermore, magnetic ground state and electronic band dispersion calculations show that the single layer EuO 2 is a metal with net magnetic moment of 5 μ B per unitcell resulting in a half-metallic ferrimagnetic behavior. Moreover, robustness of the half-metallic ferrimagnetic characteristics of EuO 2 is confirmed by the application of electric field and charging. Single layer 1T-EuO 2, with its stable ultra-thin structure and half-metallic ferrimagnetic feature, is a promising novel material for nanoscale electronic and spintronic applications.