Center for Computation and Technology, Louisiana State University, Baton Rouge, Louisiana, 70803, USA.
Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana, 70803, USA.
Sci Rep. 2017 Aug 31;7(1):10265. doi: 10.1038/s41598-017-10780-6.
The ability to predict hidden phases under extreme conditions is not only crucial to understanding and manipulating materials but it could also lead to insight into new phenomena and novel routes to synthesize new phases. This is especially true for Ruddlesden-Popper perovskite phases that possess interesting properties ranging from superconductivity and colossal magnetoresistance to photovoltaic and catalytic activities. In particular, the physical properties of the bilayer perovskite SrRuO at the surface are intimately tied to the rotation and tilt of the RuO octahedra. To take advantage of the extra degree of freedom associated with tilting we have performed first principles hybrid density functional simulations of uniaxial pressure applied along the c-axis of bulk SrRuO where we find that the octahedra become tilted, leading to two phase transitions. One is a structural transition at [Formula: see text]1.5 GPa, and the other is from a ferromagnetic (FM) metal to an antiferromagnetic (AFM) insulator at [Formula: see text]21 GPa whose AFM spin configuration is different from the AFM state near the FM ground state.
在极端条件下预测隐藏相的能力不仅对于理解和操纵材料至关重要，而且还可能为新现象和合成新相的新途径提供深入了解。这对于具有超导性、庞磁电阻、光电和催化活性等有趣性质的 Ruddlesden-Popper 钙钛矿相尤其如此。特别是，表面双层钙钛矿 SrRuO 的物理性质与 RuO 八面体的旋转和倾斜密切相关。为了利用与倾斜相关的额外自由度，我们对沿 SrRuO 体的 c 轴施加单轴压力进行了第一性原理杂化密度泛函模拟，结果发现八面体发生倾斜，导致两个相变。一个是在 [Formula: see text]1.5 GPa 处的结构相变，另一个是在 [Formula: see text]21 GPa 处从铁磁（FM）金属到反铁磁（AFM）绝缘体的转变，其 AFM 自旋构型与 FM 基态附近的 AFM 状态不同。
