[Zurück]

M. Schiebl, A. M. Shuvaev, Anna Pimenov, G. Johnstone, V. Dziom, A. Mukhin, V. Yu. Ivanov, A. Pimenov:
"Order-disorder type critical behavior at the magnetoelectric phase transition in multiferroic DyMnO3";
Physical Review B, 91 (2015), S. 224205-1 - 224205-10.

We present the results of detailed dielectric investigations of the relaxation dynamics in DyMnO3 multiferroic manganite. A strong low-frequency relaxation process near the paraelectric-ferroelectric phase transition is observed. We provide experimental evidence to show that this relaxation mode corresponds to a chirality switching of the spin cycloid in DyMnO3. We demonstrate that the relaxation dynamics in DyMnO3 is typical for an order-disorder phase transition and may be understood within a simple model with a double-well potential. These results suggest the interpretation of the paraelectric sinusoidal phase in manganites as a dynamical equilibrium of magnetic cycloids with opposite chiralities.

http://dx.doi.org/10.1103/PhysRevB.91.224205