Multiglass order and magnetoelectricity in Mn2+ doped incipient ferroelectrics
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 email@example.com
Published online: 26 June 2009
“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 Sr0.98Mn0.02TiO3 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, Tge ≈ 38 K, which is seemingly indicated by a divergence of the nonlinear susceptibility, χ3. Below Tgm ≈ 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 K0.97Mn0.03TaO3 favorably comply with the magnetoelectric multiglass concept.
PACS: 75.50.Lk – Spin glasses and other random magnets / 75.80.+q – Magnetomechanical and magnetoelectric / 77.80.Bh – Phase transitions and Curie point / 77.84.Dy – Niobates, titanates, tantalates, PZT ceramics, etc.
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2009