Polar grain boundaries in undoped SrTiO3 ceramics

• Type: Article in International Scientific Journal
• Date: 2001

Authors

Petzelt, J (Author) Other; Gregora, I (Author) Other; Rychetsky, I (Author) Other; Ostapchuk, T (Author) Other; Kamba, S (Author) Other; Vanek, P (Author) Other; Yuzyuk, Y (Author) Other; Almeida, A (Author) FCUP; Chaves, MR (Author) FCUP; Gorshunov, B (Author) Other; Dressel, M (Author) Other; Hoffmann Eifert, S (Author) Other; Waser, R (Author) Other

Journal

Title: Journal of the European Ceramic Society

Vol. 21

Pages: 2681-2686

ISSN: 0955-2219

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 13 Citations

Scopus - 12 Citations

Other information

Authenticus ID: P-000-XEQ

DOI: 10.1016/s0955-2219(01)00345-4

Abstract (EN): Raman and infra-red spectroscopic investigations of nominally pure SrTiO3 ceramics have revealed a clear presence of polar phase whose manifestation steeply increases on cooling from room temperature. The Raman strengths of the Raman-forbidden infra-red modes are proportional to omega (-alpha)(TOI) (alpha approximate to 1.5) where omega (TOI) is the polar soft mode frequency. Our explanation is based on an assumption of a temperature independent polarization Pf fixed at grain boundaries. The effective polar soft mode is slightly shifted upwards at low temperatures, becomes broader and strongly coupled with the E-g component of the structural soft mode which shows that P-f is perpendicular to the tetragonal c-axis.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 6