论文标题
在高压下Miagiif3 Perovskites中的结构相变和磁性换股
Structural phase transitions and magnetic superexchange in MIAgIIF3 perovskites at high pressure
论文作者
论文摘要
压力诱导的MIAGIIF3钙钛矿的相变，其中M = K，Rb，Cs是从理论上预测的，这是第一次被压力高达100 GPa。 M = K和RB的相变序列由正骨到单斜晶和回到正晶过渡，与角落共享无限链的逐渐弯曲相关[AGF6] 4 Minus oct oct oct oct oct oct oct ins interahedra及其通过二级Ag ... f接触... f接触。与形成鲜明对比的是，只有单个相变为三角形到三斜晶的csagf3，这与Jahn Teller-延伸的AGII的第一个协调领域的实质变形和无限链的关联相关[AGF6] 4负链条4负链进入聚合物sublattice。相变明显降低了MAGF3中链链抗铁磁性superexchange的耦合强度。
Pressure induced phase transitions of MIAgIIF3 perovskites where M = K, Rb, Cs, have been predicted theoretically for the first time for pressures up to 100 GPa. The sequence of phase transitions for M = K and Rb consists of an orthorhombic to monoclinic and back to orthorhombic transition, associated with progressive bending of infinite chains of corner sharing [AgF6]4 minus octahedra and their mutual approaching via secondary Ag...F contacts. In stark contrast, only a single phase transition i.e. tetragonal to triclinic, is predicted for CsAgF3, associated with substantial deformation of the Jahn Teller-distorted first coordination sphere of AgII and association of the infinite [AgF6]4 minus chains into a polymeric sublattice. The phase transitions markedly decrease the coupling strength of intra-chain antiferromagnetic superexchange in MAgF3 hosts lattices.
