Clarendon Laboratory, Department of Physics, University of Oxford, Oxford OX1 3PU, United Kingdom.
Istituto dei Materiali per Elettronica e Magnetismo, CNR, Area delle Scienze, 43100 Parma, Italy.
Phys Rev Lett. 2018 Jun 22;120(25):257202. doi: 10.1103/PhysRevLett.120.257202.
We present the discovery and refinement by neutron powder diffraction of a new magnetic phase in the Na_{1-x}Ca_{x}Mn_{7}O_{12} quadruple perovskite phase diagram, which is the incommensurate analogue of the well-known pseudo-CE phase of the simple perovskite manganites. We demonstrate that incommensurate magnetic order arises in quadruple perovskites due to the exchange interactions between A and B sites. Furthermore, by constructing a simple mean field Heisenberg exchange model that generically describes both simple and quadruple perovskite systems, we show that this new magnetic phase unifies a picture of the interplay between charge, magnetic, and orbital ordering across a wide range of compounds.
我们通过中子粉末衍射发现并改进了 Na_{1-x}Ca_{x}Mn_{7}O_{12} 四重钙钛矿相图中的一种新的磁性相，它是众所周知的简单钙钛矿锰氧化物准 CE 相的非简并类似物。我们证明，四重钙钛矿中出现的非简并磁序是由于 A 位和 B 位之间的交换相互作用引起的。此外，通过构建一个简单的均值场海森堡交换模型，该模型可以普遍描述简单和四重钙钛矿系统，我们表明，这种新的磁性相统一了在广泛的化合物中电荷、磁性和轨道有序之间的相互作用的图景。
