title: First-principles modeling of multiferroic RMn2O5.
abstract: We investigate the phase diagrams of RMn(2)O(5) via a first-principles effective-Hamiltonian method. We are able to reproduce the most important features of the complicated magnetic and ferroelectric phase transitions. The calculated polarization as a function of temperature agrees very well with experiments. The dielectric-constant step at the commensurate-to-incommensurate magnetic phase transition is well reproduced. The microscopic mechanisms for the phase transitions are discussed.
authors.affiliation: Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, 230026, People's Republic of China.
authors.forename: Kun
authors.initials: K
authors.lastname: Cao
authors.forename: Guang-Can
authors.initials: GC
authors.lastname: Guo
authors.forename: David
authors.initials: D
authors.lastname: Vanderbilt
authors.forename: Lixin
authors.initials: L
authors.lastname: He