Abstract
Large-scale Monte Carlo simulations are performed to analyze magnetoelectric transitions of a spin-lattice model in a magnetic field. The model explains well an experimental field-temperature phase diagram of RbCoBr. The magnetic structure in each phase is determined. Simultaneous magnetoelectric transitions observed in the zero-field case are found to occur only in the low-field region, whereas magnetic transitions and electric transitions are decoupled in the high-field region. When the spin-lattice correlation is weak, an asymmetric ferrimagnetic state and a half-ferrimagnetic state appear. The former is the intermediate state between the partial-disordered state and the ferrimagnetic state. The latter phase is characterized by a sublattice order parameter with a -- ordering pattern.
- Received 6 March 2011
DOI:https://doi.org/10.1103/PhysRevB.84.054429
©2011 American Physical Society