6H and 3C perovskites are important prototype structures in materials science. We systemically studied the structural evolution induced by the Sr²⁺-to-Ba²⁺ substitution to the parent 6H perovskite Ba₃ZnSb₂O₉. The 6H perovskite is only stable in the narrow range of x ≤ 0.2, which attributes to the impressibility of [Sb₂O₉]. The preference of 90° Sb–O–Sb connection and the strong Sb⁵⁺-Sb⁵⁺ electrostatic repulsion in [Sb₂O₉] are competitive factors to stabilize or destabilize the 6H structure when chemical pressure was introduced by Sr²⁺ incorporation. Therefore, in the following, a wide two-phase region containing 1:2 ordered 6H–Ba_2.8Sr_0.2ZnSb₂O₉ and rock-salt ordered 3C–Ba₂SrZnSb₂O₉ was observed (0.3 ≤ x ≤ 1.0). In the final, the successive symmetry descending was established from cubic (Fm3̅m, 1.3 ≤ x ≤ 1.8) to tetragonal (I4/m, 2.0 ≤ x ≤ 2.4), and finally to monoclinic (I2/m, 2.6 ≤ x ≤ 3.0). Here we proved that the electronic configurations of B-site cations, with either empty, partially, or fully filled d-shell, would also affect the structure stabilization, through the orientation preference of the B–O covalent bonding. Our investigation gives a deeper understanding of the factors to the competitive formation of perovskite structures, facilitating the fine manipulation on their physical properties.

中文翻译：

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化学取代诱导和在巴6H和3C钙钛矿结构的竞争形成_{3- X}的Sr _X ZnSb ₂ ö ₉：的两种钙钛矿的共存在0.3≤ X ≤1.0

6H和3C钙钛矿是材料科学中重要的原型结构。我们系统地研究了由Sr ²⁺到Ba ²⁺取代为母体6H钙钛矿Ba ₃ ZnSb ₂ O ₉引起的结构演化。的钙钛矿6H仅在窄范围的稳定X ≤0.2，其属性的感受性[Sb的₂ Ó ₉ ]。在[Sb ₂ O _9中，首选90°Sb–O–Sb连接和强Sb ⁵⁺ -Sb ⁵⁺静电排斥当通过Sr ²⁺引入引入化学压力时，]是稳定或破坏6H结构的竞争因素。因此，在下文中，含有1宽两相区：2个有序6H钡_2.8锶_0.2 ZnSb ₂ ö ₉和岩盐有序3C-的Ba ₂ SrZnSb ₂ ö ₉中观察到（0.3≤ X ≤1.0）。在最后的，连续的对称性下降的从立方成立（FM 3米，1.3≤ X ≤1.8）到正方晶（我4 /米，2.0≤ X≤2.4），最后到单斜晶（我2 /米，2.6≤ X ≤3.0）。在这里，我们证明了B位阳离子具有空，部分或完全填充的d-壳的电子构型，也会通过B-O共价键的取向偏好而影响结构的稳定性。我们的研究使人们对钙钛矿结构竞争形成的因素有了更深入的了解，从而有助于对其物理性质的精细控制。