CNR-IOM, UOS Cagliari, and Department of Physics, University of Cagliari, Cittadella Universitaria, Cagliari, I-09042 Monserrato, Italy.
Phys Rev Lett. 2012 Nov 21;109(21):217202. doi: 10.1103/PhysRevLett.109.217202.
We explore via density functional calculations the magnetic doping of a topological ferroelectric as an unconventional route to multiferroicity. Vanadium doping of the layered perovskite La(2)Ti(2)O(7) largely preserves electric polarization and produces robust ferromagnetic order and, hence, proper multiferroicity. The marked tendency of dopants to cluster into chains results in an insulating character at generic doping. Ferromagnetism stems from the symmetry breaking of the multiorbital V system via an unusual "antiferro"-orbital order, and from the host's low-symmetry layered structure.
我们通过密度泛函计算探索了拓扑铁电体的磁性掺杂，这是一种实现多铁性的非常规途径。钒掺杂层状钙钛矿 La(2)Ti(2)O(7) 在很大程度上保留了电极化，并产生了稳定的铁磁性有序，从而实现了适当的多铁性。掺杂剂倾向于形成链状聚集体，导致在一般掺杂情况下呈现绝缘性质。铁磁性源于多轨道 V 系统通过不寻常的“反铁磁”轨道有序的对称性破缺，以及宿主的低对称层状结构。
