下地幔硅酸盐矿物的结构和电子相变对其高压下光学性质的影响

发布时间：2018-06-15 02:10

本文选题：结构相变 + 光学性质　；参考：《原子与分子物理学报》2017年02期

【摘要】：基于第一性原理平面波超软赝势法并结合局域密度近似,计算了(Mg_(0.875),Fe_(0.125))SiO_3钙钛矿和(Mg_(0.9),Fe_(0.1))SiO_3后钙钛矿晶体在高压下的光学性质.计算数据表明:(1)钙钛矿的结构相变将导致其吸收性增强,证实了基于实验数据的推断.(2)后钙钛矿二价铁吸收带的波数位置与实验观测结果相近.(3)在后钙钛矿相区,压力将导致吸收带的强度缓慢增加,但二价铁自旋态的转变对其吸收谱的影响却非常微弱.(4)钙钛矿的结构相变将导致其折射率升高;在后钙钛矿相区,压力及自旋态转变对折射率的影响不明显.(5)波数大约在12500 cm~(-1)以下,后钙钛矿折射率随波数的增加而降低,钙钛矿的折射率则变化不大;波数大约在12500 cm~(-1)以上,钙钛矿折射率随波数的增加而增大,后钙钛矿的折射率则显著上升.
[Abstract]:Based on the first-principle plane-wave ultra-soft pseudopotential method and local density approximation, the optical properties of the perovskite crystals in the post-stack perovskite crystals have been calculated under high pressure. The calculated data show that the structural phase transition of the perovskite will increase its absorbability. It is confirmed that the wavenumber position of the absorption band of perovskite divalent iron based on the experimental data is similar to that of the experimental observation. 3) in the post-perovskite phase region, The intensity of absorption band will increase slowly due to pressure, but the effect of divalent iron spin state transformation on absorption spectrum is very weak. The structural phase transition of perovskite will lead to the increase of refractive index in the post-perovskite phase region, and in the post-perovskite phase region, the structure phase transition of perovskite will lead to the increase of refractive index. The influence of pressure and spin state transition on refractive index is not obvious. The wavenumber of perovskite is less than 12500 cm ~ (-1). After that, the refractive index of perovskite decreases with the increase of wave number, but the refractive index of perovskite does not change much, and the wave number is above 12500 cm ~ (-1). The refractive index of perovskite increases with the increase of wave number, but the refractive index of perovskite increases significantly after the increase of wave number.
【作者单位】：四川师范大学物理与电子工程学院固体物理研究所;成都职业技术学院基础部;中国工程物理研究院流体物理研究所冲击波物理与炮轰物理重点实验室;
【基金】：中国工程物理研究院科学基金资助项目(2010A0201005) 四川省教育厅科技基金资助的课题(13ZA0152)
【分类号】：O469

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