Raman scattering in sol-gel derived PbTiO3 films modified with Ca

• Tipo: Artigo em Revista Científica Internacional
• Data: 2004

Autores

Kholkin, AL (Autor) Outra; Bdikin, I (Autor) Outra; Yuzyuk, YI (Autor) Outra; Almeida, A (Autor) FCUP; Chaves, MR (Autor) Outra; Calzada, ML (Autor) Outra; Mendiola, J (Autor) Outra

Revista

Título: Materials Chemistry and Physics

Vol. 85

Páginas: 176-179

ISSN: 0254-0584

Editora: Elsevier

Indexação

ISI Web of Knowledge - 11 Citações

Scopus - 11 Citações

Outras Informações

ID Authenticus: P-000-ACR

DOI: 10.1016/j.matchemphys.2004.01.001

Abstract (EN): X-ray diffraction (XRD) and Raman scattering in sol-gel derived Ph1-x CaxTiO3(PCT)thin films are studied as a function of Ca content x. It is found that Ca2+ addition to PbTiO3 films results in a gradual decrease of tetragonality of the perovskite lattice accompanied with a considerable modification of the Raman spectra. A significant difference in Raman spectra of PCT films and available reference data for single crystals (x = 0) is explained in terms of the large internal stress, small grain size, and structural disorder produced by Ca2+ substitution. It is found that the shift of the frequency of ferroelectric soft mode correlates well with the variation of tetragonality for x less than or equal to x(c) = 0.4. The concentration dependence of the shift is strongly non-linear being qualitatively different from that observed earlier in other A-site doped lead fitanate-based systems. According to XRD data, the averaged crystal structure for x(c) approximate to 0.4 appears as pseudo-cubic, while Raman scattering revealed short-range order tetragonal distortion. The structural characteristics of PCT films are linked to their electromechanical properties measured earlier by interferometric technique.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 4