标题： 反铁畸变钙钛矿的Ruddlesden-Popper相中八面体旋转的影响 显示英文标题

标题： Impact of octahedral rotations on Ruddlesden-Popper phases of antiferrodistortive perovskites

摘要： 这项工作对反铁畸变（AFD）钙钛矿中的Ruddlesden-Popper（RP）相的结构构型进行了迄今为止最详细和广泛的理论研究，并制定了一项研究计划，该计划可以用于任何AFD钙钛矿系统的RP相研究。 我们系统地研究了氧八面体旋转对AFD钙钛矿（A_n+1 B_n O_3n+1）中RP相能量的影响，对于n = 1...30的情况，提供了n --> infinity时的渐近结果，这些结果给出了堆垛缺陷之间相互作用的形式以及这种堆垛缺陷在孤立状态下的行为。 我们发现缺陷之间存在与距离成反比的相互作用，其强度根据八面体的构型不同而变化多达两倍。 我们发现这种效应的强度足以（a）相对于分解为块体钙钛矿和块体A-氧化物来稳定或不稳定RP相，以及（b）足够大地影响RP相的能量尺度，从而限制邻近堆垛缺陷的八面体的旋转状态，即使在块体区域的八面体自由摆动的温度下也是如此。 最后，我们提供了证据，表明八面体旋转的重要性可以从RP堆垛缺陷两侧氧离子之间距离的变化来理解。 显示英文摘要

摘要： This work presents the most detailed and extensive theoretical study to date of the structural configurations of Ruddlesden-Popper (RP) phases in antiferrodistortive (AFD) perovskites and formulates a program of study which can be pursued for RP phases of any AFD perovskite system. We systematically investigate the effects of oxygen octahedral rotations on the energies of RP phases in AFD perovskites (A_n+1 B_n O_3n+1) for n = 1...30, providing asymptotic results for n --> infinity that give both the form of the interaction between stacking faults and the behavior of such stacking faults in isolation. We find an inverse-distance interaction between faults with a strength which varies by as much as a factor of two depending on the configuration of the octahedra. We find that the strength of this effect can be sufficient to (a) stabilize or destabilize the RP phase with respect to dissociation into the bulk perovskite and the bulk A-oxide and (b) affect the energy scales of the RP phase sufficiently to constrain the rotational states of the octahedra neighboring the stacking faults, even at temperatures where the octahedra in the bulk regions librate freely. Finally, we present evidence that the importance of the octahedral rotations can be understood in terms of changes in the distances between oxygen ions on opposing sides of the RP stacking faults.