Polar grain boundaries in undoped SrTiO3 ceramics

• Tipo: Artigo em Revista Científica Internacional
• Data: 2001

Autores

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

Revista

Título: Journal of the European Ceramic Society

Vol. 21

Páginas: 2681-2686

ISSN: 0955-2219

Editora: Elsevier

Indexação

ISI Web of Knowledge - 13 Citações

Scopus - 12 Citações

Outras Informações

ID Authenticus: 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.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 6