Electronic Structure, Phonons and Dielectric Anomaly in Ferromagnetic Insulating Double Perovskite La2NiMnO6
arXiv:0805.1112 · doi:10.1103/PhysRevLett.100.186402
Abstract
Using first-principles density functional calculations, we study the electronic and magnetic properties of ferromagnetic insulating double-perovskite compound La2NiMnO6, which has been reported to exhibit interesting magnetic field sensitive dielectric anomaly as a function of temperature. Our study reveals existence of very soft infra-red active phonons that couple strongly with spins at the Ni and Mn sites through modification of the super-exchange interaction. We suggest that these modes are the origin for observed dielectric anomaly in La2NiMnO6.
4 pages,3 figures