Gigantic Magnetoelectric Effect in Manganese Tungstate


The relationship between magnetic order and ferroelectric properties has been investigated for MnWO4 with long-wavelength magnetic structure. Spontaneous electric polarization is observed in an elliptical spiral spin phase. The magnetic-field dependence of electric polarization indicates that the noncollinear spin configuration plays a key role for the appearance of ferroelectric phase. An electric polarization flop from the b direction to the a direction has been observed when a magnetic field above 10T is applied along b axis. This result demonstrates that an electric polarization flop can be induced by a magnetic field. This is the first example of gigantic magnetoelectric effects in simple systems without rare-earth f-moments.

IMRAM, Tohoku University: K. Taniguchi, N. Abe, T. Arima
IMR, Tohoku University: T. Takenobu, Y. Iwasa


東北大学多元物質科学研究所:谷口耕治, 阿部伸之, 有馬孝尚
東北大学金属材料研究所:竹延大志, 岩佐義宏