Large flexoelectric anisotropy in paraelectric Barium Titanate

The bending-induced polarization of barium titanate single crystals has been measured with an aim to elucidate the origin of the large difference between theoretically predicted and experimentally measured flexoelectricity in this material. The results indicate that part of the difference is due to...

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Detalles Bibliográficos
Autores: Narvaez, Jackeline, Saremi, Sahar, Hong, Jiawang, Stengel, Massimiliano|||0000-0003-4175-3888, Catalan, Gustau|||0000-0003-0214-4828
Tipo de recurso: artículo
Fecha de publicación:2015
País:España
Institución:Universitat Autònoma de Barcelona
Repositorio:Dipòsit Digital de Documents de la UAB
Idioma:inglés
OAI Identifier:oai:ddd.uab.cat:212912
Acceso en línea:https://ddd.uab.cat/record/212912
https://dx.doi.org/urn:doi:10.1103/PhysRevLett.115.037601
Access Level:acceso abierto
Palabra clave:Cubic materials
Flexoelectricity
Induced polarization
Large anisotropy
Macroscopic bending
Oriented crystals
Short range ordering
Surface piezoelectricities
Descripción
Sumario:The bending-induced polarization of barium titanate single crystals has been measured with an aim to elucidate the origin of the large difference between theoretically predicted and experimentally measured flexoelectricity in this material. The results indicate that part of the difference is due to polar regions (short-range order) that exist above TC and up to T∗≈200-225°C. Above T∗, however, the flexovoltage coefficient still shows an unexpectedly large anisotropy for a cubic material, with (001)-oriented crystals displaying 10 times more flexoelectricity than (111)-oriented crystals. Theoretical analysis shows that this anisotropy cannot be a bulk property, and we therefore interpret it as indirect evidence for the theoretically predicted but experimentally elusive contribution of surface piezoelectricity to macroscopic bending-induced polarization.