title: Tiny cause with huge impact: polar instability through strong magneto-electric-elastic coupling in bulk EuTiO3.
abstract: EuTiO3 exhibits strong magneto-electric coupling at the onset of antiferromagnetic order below TN = 5.7 K. The dielectric permittivity drops at TN by 7% and recovers to normal values with increasing magnetic field. This effect is shown to stem from tiny lattice effects as seen in magnetostriction data which directly affect the soft optic mode and its polarizability coordinate. By combining experimental results with theory we show that marginal changes in the lattice parameter of the order of 0.01% have a more than 1000% effect on the transverse optic soft mode of ETO and thus easily induce a ferroelectric instability.
authors.affiliation: Max-Planck-Institute for Solid State Research, Heisenbergstr. 1, D-70569 Stuttgart, Germany.
authors.forename: Patrick
authors.initials: P
authors.lastname: Reuvekamp
authors.forename: Kevin
authors.initials: K
authors.lastname: Caslin
authors.forename: Zurab
authors.initials: Z
authors.lastname: Guguchia
authors.forename: Hugo
authors.initials: H
authors.lastname: Keller
authors.forename: Reinhard K
authors.initials: RK
authors.lastname: Kremer
authors.forename: Arndt
authors.initials: A
authors.lastname: Simon
authors.forename: Jürgen
authors.initials: J
authors.lastname: Köhler
authors.forename: Annette
authors.initials: A
authors.lastname: Bussmann-Holder