Eur. Phys. J. B 75, 439-442 (2010)
https://doi.org/10.1140/epjb/e2010-00143-1

The magnetoelectric effects in weak ferromagnetic YMn₂O₅ modulated structure: a Landau theory approach

¹ Department of Physics and Laser and Plasma Research Institute, Shahid Beheshti University, G.C., Evin, Tehran, 19839, Iran
² Department of Physics, Azarbaijan University of Tarbiat Moallem, 35th km Tabriz-Maragheh Road, 53714-161, Tabriz, Iran

Corresponding author: ^a Phirouznia@azaruniv.edu

Received: 23 September 2009
Published online: 12 May 2010

Abstract

According to the group theory approach, linear magnetoelectric effect (ME) can not be obtained for the spatial group of YMn₂O₅, which was known to be mmm. Regard to the magnetic structure of these type of materials, we propose a magnetic group structure for the YMn₂O₅ by considering spin orientation of the Mn³⁺ and Mn⁴⁺ ions. According to the landau theory of phase transition it can be shown, how symmetrical rules result in relationship between quantities such as magnetic order, polarization, and etc. This relation shows a weak ferromagnetic state, associated with spontaneous polarization, arisen by Dzyaloshinskii-Moriya type interaction and a field induced change in magnetoelectrical susceptibility.