TY  - JOUR
AU  - Hanzig, Juliane
AU  - Mehner, Erik
AU  - Jachalke, Sven
AU  - Hanzig, Florian
AU  - Zschornak, Matthias
AU  - Richter, Carsten
AU  - Leisegang, Tilmann
AU  - Stoecker, Hartmut
AU  - Meyer, Dirk C.
TI  - Dielectric to pyroelectric phase transition induced by defect migration
JO  - New journal of physics
VL  - 17
IS  - 2
SN  - 1367-2630
CY  - [Bad Honnef]
PB  - Dt. Physikalische Ges.
M1  - PUBDB-2016-00294
SP  - 023036 -
PY  - 2015
AB  - 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.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000352865200015
DO  - DOI:10.1088/1367-2630/17/2/023036
UR  - https://bib-pubdb1.desy.de/record/293129
ER  -