Abstract
Magnetic-field-induced spin flop transition and magnetoelectric effect in noncentrosymmetric (0.5 1) single crystals have been investigated. Temperature dependence of magnetic susceptibility shows that the compounds have antiferromagnetic transition temperatures above room temperature. The spin easy axis varies from the axis to the axis with increasing Al content . When a magnetic field is applied along the spin easy axis, a spin flop transition takes place, accompanied by anomalies in the electric polarization and dielectric constant. The anomalies can be ascribed to a noncollinear spin arrangement in the domain walls between two magnetic phases and/or the spin direction dependent modulation of the metal-ligand hybridization. Such a polarization change with a spin flop transition in polar antiferromagnets may provide a route to realize large magnetoelectric coupling at high temperatures.
- Received 29 August 2013
- Revised 14 February 2014
DOI:https://doi.org/10.1103/PhysRevB.89.054437
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