Ferroelectricity and giant magnetocapacitance in perovskite rare-earth manganites.
The relationships among magnetism, lattice modulation, and dielectric properties have been investigated for RMnO3 (R=Eu, Gd, Tb, and Dy). These compounds show a transition to an incommensurate lattice structure below their Néel temperature, and subsequently undergo an incommensurate-commensurate (IC-C) phase transition. For TbMnO3 and DyMnO3 it was found that the IC-C transition is accompanied by a ferroelectric transition, associated with a lattice modulation in the C phase. DyMnO3 shows a gigantic magnetocapacitance with a change of dielectric constant up to Deltaepsilon/epsilon approximately 500%.
Goto
T
T
Department of Applied Physics, University of Tokyo, Tokyo 113-8656, Japan.
Kimura
T
T
Lawes
G
G
Ramirez
A P
AP
Tokura
Y
Y