Eur. Phys. J. B 71, 407-410 (2009)
https://doi.org/10.1140/epjb/e2009-00222-4

Multiglass order and magnetoelectricity in Mn²⁺ doped incipient ferroelectrics

¹ Angewandte Physik, Universität Duisburg-Essen, Lotharstr. 1, 47048 Duisburg, Germany
² Institute of Physics, University of Silesia, 40-007 Katowice, Poland
³ Department of Ceramics and Glass Engineering, CICECO, University of Aveiro, 3810-193 Aveiro, Portugal

Corresponding author: ^a wolfgang.kleemann@uni-due.de

Received: 3 March 2009
Published online: 26 June 2009

Abstract

“Multiglass” materials with simultaneous occurrence of two different glassy states extend the frame of conventional multiferroicity, which is devoted to crystalline materials with coexisting uniform long-range electric and magnetic ordering. The concept applies to Sr_0.98Mn_0.02TiO₃ ceramics, where A-site substituted Mn²⁺ ions are at the origin of both a polar and a spin cluster glass. Spin freezing is initiated below the dipolar glass temperature, T_g^e ≈ 38 K, which is seemingly indicated by a divergence of the nonlinear susceptibility, χ₃. Below T_g^m ≈ 34 K both glass phases are independently verified by memory and rejuvenation effects. Biquadratic interaction of the Mn²⁺ spins with ferroelectric correlations of their off-center pseudospins in the incipient ferroelectric host crystal SrTiO₃ explains the high spin glass temperature and comparably strong third-order magnetoelectric coupling between the polar and the magnetic degrees of freedom. Preliminary results on the related compound K_0.97Mn_0.03TaO₃ favorably comply with the magnetoelectric multiglass concept.