Artigo
Structural, ferroelectric, and optical properties of Pb0.60Ca0.20Sr0.20TiO3, Pb0.50Ca0.25Sr0.25TiO3 and Pb0.40Ca0.30Sr0.30TiO3 thin films prepared by the chemical solution deposition technique
Registro en:
Ceramics International. Oxford: Elsevier Sci Ltd, v. 40, n. 8, p. 13363-13370, 2014.
0272-8842
10.1016/j.ceramint.2014.05.052
WOS:000340321300096
Autor
Pontes, D. S. L.
Pontes, F. M. [UNESP]
Capeli, R. A. [UNESP]
Garzim, M. L. [UNESP]
Chiquito, A. J.
Longo, E. [UNESP]
Resumen
Perovskite ferroelectric Pb0.60Ca0.20Sr0.20TiO3, Pb0.50Ca0.25Sr0.25TiO3 and Pb0.40Ca0.30Sr0.30TiO3, thin films were deposited on Pt/Ti/SiO2/Si and (1 0 0) LaAlO3 substrates by a chemical solution deposition method. XRD revealed the formation of pure thin films on both substrates. All thin films have very flat surfaces, and no droplets were found on their surfaces. Raman data showed a gradual phase transition from tetragonal to a pseudocubic perovskite structure in these thin films; a simultaneous increase in Ca and Sr contents at room temperature was also observed. Temperature-dependent dielectric permittivity measurements revealed a decreasing ferroelectric-to-paraelectric phase transition temperature with increasing Ca and Sr contents. At 100 kHz, ferroelectric-to-paraelectric phase transition temperatures were approximately 505, 355 and 290 K for Pb0.60Ca0.20Sr0.20TiO3, Pb0.50Ca0.25Sr0.25TiO3 and Pb0.40Ca0.30Sr0.30TiO3 thin films, respectively. The E-g of the films were estimated from Tauc's law and were found to be inversely dependent on the Ca and Sr content amounts. (C) 2014 Elsevier Ltd and Techna Group S.r.l. All rights reserved. Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Univ Fed Sao Carlos, Dept Chem, LIEC, BR-13565905 Sao Paulo, Brazil Univ Estadual Paulista Unesp, Dept Chem, BR-17033360 Sao Paulo, Brazil Univ Sao Paulo, Inst Fis Sao Carlos, BR-13560250 Sao Paulo, Brazil Univ Fed Sao Carlos, NanO LaB, Dept Phys, BR-13565905 Sao Paulo, Brazil Univ Estadual Paulista Unesp, Inst Chem, Sao Paulo, Brazil Univ Estadual Paulista Unesp, Dept Chem, BR-17033360 Sao Paulo, Brazil Univ Estadual Paulista Unesp, Inst Chem, Sao Paulo, Brazil