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 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, T-g (e) a parts per thousand 38 K, which is seemingly indicated by a divergence of the nonlinear susceptibility, chi(3). Below T-g (m) a parts per thousand 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.
keywords
STRONTIUM-TITANATE CERAMICS; ORIENTATIONAL GLASSES; SPIN-GLASSES
subject category
Physics
authors
Kleemann, W; Bedanta, S; Borisov, P; Shvartsman, VV; Miga, S; Dec, J; Tkach, A; Vilarinho, PM
our authors
Oleksandr Tkach
Assistant Researcher
Paula Maria Lousada Silveirinha Vilarinho
Vice Directoracknowledgements
Fruitful discussions with Rasa Pirc, Ljubljana, are gratefully acknowledged. Thanks are due to the Deutsche Forschungsgemeinschaft (SFB 491, KL306/38-4), the EU ( STREP