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arXiv · 1103.5294

Magnetic-field induced competition of two multiferroic orders in a triangular-lattice helimagnet MnI2

T. Kurumaji·S. Seki·S. Ishiwata·H. Murakawa·Y. Tokunaga·Y. Kaneko·Y. Tokura
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Abstract

Magnetic and dielectric properties with varying magnitude and direction of magnetic field H have been investigated for a triangular lattice helimagnet MnI2. The in-plane electric polarization P emerges in the proper screw magnetic ground state below 3.5 K, showing the rearrangement of six possible multiferroic domains as controlled by the in-plane H. With every 60-degree rotation of H around the [001]-axis, discontinuous 120-degree flop of P-vector is observed as a result of the flop of magnetic modulation vector q. With increasing the in-plane H above 3 T, however, the stable q-direction changes from q||<1-10> to q||<110>, leading to a change of P-flop patterns under rotating H. At the critical field region (~3 T), due to the phase competition and resultant enhanced q-flexibility, P-vector smoothly rotates clockwise twice while H-vector rotates counter-clockwise once.

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T. Kurumaji, S. Seki, S. Ishiwata, H. Murakawa, Y. Tokunaga, Y. Kaneko, Y. Tokura. 2011-03-28. Magnetic-field induced competition of two multiferroic orders in a triangular-lattice helimagnet MnI2. https://doi.org/10.1103/physrevlett.106.167206

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