Magnetically-Driven Ferroelectric Atomic Displacements in perovskite like YMnO3

D. Okuyama; S. Ishiwata; Y. Takahashi; K. Yamauchi; S. Picozzi; K. Sugimoto; H. Sakai; M. Takata; R. Shimano; Y. Taguchi; T. Arima; Y. Tokura

doi:10.1103/PhysRevB.84.054440

paper

Magnetically-Driven Ferroelectric Atomic Displacements in perovskite like YMnO3

arXiv:1107.2467 · doi:10.1103/PhysRevB.84.054440

Abstract

Magnetically-driven ferroelectric atomic displacements of the order of 10 $^{- 3} A n g s t r o mha v e b ee n o b ser v e d in or t h or h o mbi c (p er o v s k i t e l ik e) Y M n O$ _3 $b y a s in g l e - cr y s t a l sy n c h r o t r o n x - r a y d i f f r a c t i o n . T h er e f in e d p o l a r s t r u c t u r es h o w s t h ec ha r a c t er i s t i c b o n d a l t er na t i o n d r i v e nb y t h ee x c han g es t r i c t i o nin s t a g g er e d M n - O - M na r r a y s w i t h$ \uparrow\uparrow\downarrow\downarrow$ type ordering, giving rise to a spontaneous polarization along a-axis. First-principles calculations based on the Berry phase method as well as on the experimentally refined crystal structure can reproduce the observed polarization value.

8 pages, 5 figures, 2 tables