Intercalating Helium into A-Site Vacant Perovskites
Intercalating Helium into A-Site Vacant Perovskites
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DOI：
10.1021/acs.chemmater.3c00353
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发表时间：
2023-03
影响因子：
8.6
通讯作者：
Stefano Racioppi;Mao-Peng Miao;E. Zurek
中科院分区：
文献类型：
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作者：
Stefano Racioppi;Mao-Peng Miao;E. Zurek
采用进化搜索来预测在 A 位上具有氦原子的钙钛矿在压力高达 10 GPa 的情况下最稳定的结构。通过密度泛函理论（DFT）计算研究了与氦嵌入[CaZr]F6相关的热力学、[He]2[CaZr]F6在压力下采用的结构以及母体钙钛矿和含氦相的机械性能。发现了有利于从元素氦和空位 A 位钙钛矿形成 HeAlF3、HeGaF3、HeInF3、HeScF3 和 HeReO3 的压力-温度条件。我们的 DFT 计算表明，熵可以稳定充氦的钙钛矿，只要稀有气体原子在其孔内占据的体积大于该压力下元素固体内的体积。我们发现，氦的掺入会将 AlF3 的体积模量从锡的特征值增加到钢的特征值，并阻碍其八面体在压力下发生的旋转。
Evolutionary searches were employed to predict the most stable structures of perovskites with helium atoms on their A-sites up to pressures of 10 GPa. The thermodynamics associated with helium intercalation into [CaZr]F6, structure that [He]2[CaZr]F6 adopts under pressure, and the mechanical properties of the parent perovskite and helium-bearing phase were studied via density functional theory (DFT) calculations. The pressure-temperature conditions where the formation of HeAlF3, HeGaF3, HeInF3, HeScF3 and HeReO3 from elemental helium and the vacant A-site perovskites is favored were found. Our DFT calculations show that entropy can stabilize the helium-filled perovskites provided that the volume that the noble gas atom occupies within their pores is larger than within the elemental solid at that pressure. We find that helium incorporation will increase the bulk modulus of AlF3 from a value characteristic of tin to one characteristic of steel, and hinders rotations of its octahedra that occur under pressure.