Regensburg 2010 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 33: Topical Session Multifunctional Materials II

MM 33.1: Topical Talk

Mittwoch, 24. März 2010, 12:00–12:30, H6

Strain-dependent ferroic properties of doped LaMO₃ (M = Mn or Co) and BiFeO₃ — •Kathrin Dörr¹, Diana Rata¹, Andreas Herklotz¹, Orkidia Bilani¹, Martina Dekker¹, Ludwig Schultz¹, Marianne Reibold², Michael Biegalski³, and Hans Christen³ — ¹IFW Dresden, Postfach 270116, 01171 Dresden, Germany — ²Technische Universität Dresden, Speziallabor Triebenberg, 01328 Dresden, Germany — ³Oak Ridge National Laboratory, CNMS, PO Box 2008, Bethel Valley Rd.,Oak Ridge, TN 37831, USA

Elastic strain at epitaxially grown interfaces provides an efficient coupling mechanism in two-phase multiferroics: piezoelectric or magnetostrictive strain arising from application of an electric or a magnetic field is transferred readily between the components. We employ a piezoelectric single-crystalline substrate to apply reversible biaxial strain to epitaxially grown magnetic or ferroelectric films and study the strain response of their ferroic properties. The relaxor-based 0.72PbMg_1/3Nb_2/3O₃ -0.28PbTiO₃(001) (PMN-PT) proved to be a favourable piezo-substrate with large, reversible, uniform in-plane strain which shows little temperature dependence. The magnetization vs. strain of doped LaMO₃ (M = Mn or Co) phases has been studied. It reveals the impact of the strain-induced tetragonal lattice distortion on the ferromagnetic double exchange and the magnetic moment of Co ions that leads to moderate or large magnetization modulation. Further, the strain dependence of ferroelectric switching has been investigated for multiferroic BiFeO₃. It displays a large response of unexpected sign attributed to a strain influence on kinetics.