On the magnetoelectric effect in paramagnetic NH2(CH3)(2)Al1-XCrX(SO4)(2)center dot 6H(2)O crystals

摘要

The recently reported ability to induce and tune a sign of the magnetoelectric (ME) interactions in NH2(CH3)(2)Al1-xCrx(SO4)(2)center dot 6H(2)O crystals as a function of Cr content is further investigated here. The ME coupling and its larger absolute value for the sample with larger Cr content agrees qualitatively with thermodynamic Landau analysis. However, quantitative estimation implies other contributions as well. The observed nontrivial magnetic field dependence of ferroelectric transition can be explained within the model that takes into account influence of the arising local deformation of the lattice on the two types of DMA group responsible respectively for the ferroelectric and antiferroelectric ordering. Published under license by AIP Publishing.