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arXiv · 0811.4015

Mechanism of Lattice-Distortion-Induced Electric-Polarization Flop in the Multiferroic Perovskite Manganites

Masahito Mochizuki·Nobuo Furukawa
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Abstract

Magnetoelectric phase diagrams of the perovskite manganites, Eu1-xYxMnO3 and Gd1-xTbxMnO3, are theoretically studied. We first construct a microscopic model, and then analyze the model using the Monte-Carlo method. We reproduce the diagrams, which contain two different multiferroic states, i.e., the ab-plane spin cycloid with electric polarization P//a and the bc-plane spin cycloid with P//c. We reveal that their competition originates from a conflict between the single-ion anisotropy and the Dzyaloshinsky-Moriya interaction, which is controlled by the second-neighbor spin exchanges enhanced by the GdFeO3-type distortion. This leads to a P flop from a to c with increasing x in agreement with the experiments.

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Masahito Mochizuki, Nobuo Furukawa. 2009-10-28. Mechanism of Lattice-Distortion-Induced Electric-Polarization Flop in the Multiferroic Perovskite Manganites. https://doi.org/10.1143/jpsj.78.053704%2C%2010.1143%2Fjpsj.78.118002

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