%0 Journal Article
%A Hanzig, Juliane
%A Mehner, Erik
%A Jachalke, Sven
%A Hanzig, Florian
%A Zschornak, Matthias
%A Richter, Carsten
%A Leisegang, Tilmann
%A Stoecker, Hartmut
%A Meyer, Dirk C.
%T Dielectric to pyroelectric phase transition induced by defect migration
%J New journal of physics
%V 17
%N 2
%@ 1367-2630
%C [Bad Honnef]
%I Dt. Physikalische Ges.
%M PUBDB-2016-00294
%P 023036 -
%D 2015
%X Subjecting strontium titanate single crystals to an electric field in the order of 10<sup>6</sup> V m<sup>−1</sup> is accompanied by a distortion of the cubic crystal structure, so that inversion symmetry vanishes and a polar phase is established. Since the polar nature of the migration-induced field-stabilized polar (MFP) phase is still unclear, the present work investigates and confirms the pyroelectric structure. We present measurements of thermally stimulated and pyroelectric currents that reveal a pyroelectric coefficient p<sub>MFP</sub> in the order of 30 μC K<sup>−1</sup>m<sup>−2</sup>. Therefore, a dielectric to pyroelectric phase transition in an originally centrosymmetric crystal structure with an inherent dipole moment is found, which is induced by defect migration. From symmetry considerations, we derive space group P<sub>4mm</sub> for the MFP phase of SrTiO<sub>3</sub>. The entire electroformation cycle yields additional information about the directed movement and defect chemistry of oxygen vacancies.
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000352865200015
%R 10.1088/1367-2630/17/2/023036
%U https://bib-pubdb1.desy.de/record/293129