论文标题
在超高压力下铁（mg，fe）o的铁总自旋的结构过渡和重新出现
Structural transition and re-emergence of iron's total electron spin in (Mg,Fe)O at ultrahigh pressure
论文作者
论文摘要
含有Fe的MGO [（Mg $ _ {1-X} $ Fe $ _x $）O]被认为是陆生系外行星的主要组成部分。地球下地幔中的B1结构结晶（mg $ _ {1-x} $ fe $ _x $）o o在$ 45 gpa的高旋转（$ s = 2 $）的高旋转（$ s = 2 $）过渡时（$ \ s = 0 $）过渡，$ 45 gpa，伴随着矿物质的物理属性（$ senteries norteriess note nortiand of senteries norties note nortiess note in Intermed notiess note note note normed notiess note）（在这项工作中，我们调查（mg $ _ {1-x} $ fe $ _x $）o（$ x \ leq 0.25 $），通过第一原理计算，最高$ 1.8 $ tpa。我们的计算表明（毫克$ _ {1-x} $ fe $ _x $）o o同时进行结构性和自旋过渡，以$ \ sim $ 0.6 tpa，从B1相低旋转状态到B2相中的中间型旋转状态，FE的总电子旋转$ S $从$ 0 $ $ 1 $ 1 $ 1 $ 1 $ 1 $ 1 $ 1 $ 1 $ 1 $ 1 $ 1。进一步压缩后，在B2相中发生了中间至低的自旋跃迁。根据FE浓度（$ x $），金属$ - $绝缘体过渡和菱形扭曲也可能在B2阶段发生。这些结果表明，铁和自旋过渡可能会影响巨大压力范围内的行星内部。
Fe-bearing MgO [(Mg$_{1-x}$Fe$_x$)O] is considered a major constituent of terrestrial exoplanets. Crystallizing in the B1 structure in the Earth's lower mantle, (Mg$_{1-x}$Fe$_x$)O undergoes a high-spin ($S=2$) to low-spin ($S=0$) transition at $\sim$45 GPa, accompanied by anomalous changes of this mineral's physical properties, while the intermediate-spin ($S=1$) state has not been observed. In this work, we investigate (Mg$_{1-x}$Fe$_x$)O ($x \leq 0.25$) up to $1.8$ TPa via first-principles calculations. Our calculations indicate that (Mg$_{1-x}$Fe$_x$)O undergoes a simultaneous structural and spin transition at $\sim$0.6 TPa, from the B1 phase low-spin state to the B2 phase intermediate-spin state, with Fe's total electron spin $S$ re-emerging from $0$ to $1$ at ultrahigh pressure. Upon further compression, an intermediate-to-low spin transition occurs in the B2 phase. Depending on the Fe concentration ($x$), metal$-$insulator transition and rhombohedral distortions can also occur in the B2 phase. These results suggest that Fe and spin transition may affect planetary interiors over a vast pressure range.
