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

• Type: Article in International Scientific Journal
• Date: 2004

Authors

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

Journal

Title: Materials Chemistry and Physics

Vol. 85

Pages: 176-179

ISSN: 0254-0584

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 11 Citations

Scopus - 11 Citations

Other information

Authenticus ID: 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.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 4