Effects of strontium and calcium simultaneous substitution on electrical and structural properties of Pb1-x-y Ca (x) Sr (y) TiO3 thin films

Autor(es)

Pontes, D. S. L. ^[1] ; Longo, E. ^[1] ; Pontes, F. M. ^[2] ; Galhiane, M. S. ^[2] ; Santos, L. S. ^[2] ; Pereira-da-Silva, Marcelo A. ^{[3, 4]} ; da Silva, J. H. D. ^[5] ; Chiquito, A. J. ^[6] ; Pizani, P. S. ^[6]

Afiliação do(s) autor(es)

^[1] Univ Estadual Paulista, Inst Chem, BR-14801970 Sao Paulo - Brazil

^[2] Univ Estadual Paulista, Dept Chem, LAMAC, BR-17033360 Sao Paulo - Brazil

^[3] UNICEP, Ctr Univ Cent Paulista, BR-13563470 Sao Carlos, SP - Brazil

^[4] Univ Sao Paulo, Inst Fis, BR-13560250 Sao Carlos, SP - Brazil

^[5] Sao Paulo State Univ, UNESP, Adv Mat Grp, Dept Phys, BR-13563470 Bauru, SP - Brazil

^[6] Univ Fed Sao Carlos, Dept Phys, BR-13565905 Sao Carlos, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING; v. 96, n. 3, p. 731-740, AUG 2009.
• Citações Web of Science: 3

Resumo

Ferroelectric Pb(1-x-y) Ca (x) Sr (y) TiO(3) thin films (denoted by PCST90, PCST70, and PCST30) were deposited on the Pt/Ti/SiO(2)/Si substrates by a chemical solution deposition method. Their properties were investigated from the viewpoint of crystal structure, microstructure, dielectric, and ferroelectric properties. X-ray diffraction patterns revealed the formation of PCST90, PCST70, and PCST30 thin films without any secondary phases. Infrared and Raman spectroscopy results show that a gradual phase transition from tetragonal to pseudocubic or cubic perovskite structure may occur in PCST thin films with the simultaneous increase of Ca(2+) and Sr(2+) contents. Both substitution of isovalent Ca(2+) and Sr(2+) at Pb(2+)-site enhanced the dielectric constant and reduced the remnant polarization. In addition, ferroelectric test analyses show that the PCST thin films undergo a ferroelectric-to-paraelectric phase transformation with an amount of Pb(2+), Ca(2+), and Sr(2+) at 30%, 35%, and 35% mol, respectively. Hence, the absence of ferroelectric property may be attributed to a decreasing of the octahedron distortion in the perovskite structure accompanied by a weakening of long-range ferroelectric order. (AU)

• Processo FAPESP: 06/51640-6 - Estudo sobre a cristalização de nanopartículas e nanofilmes cerâmicos ferroelétricos por micro-ondas e por forno de alta pressão
• Beneficiário: Debora da Silva Lima Pontes
• Modalidade de apoio: Bolsas no Brasil - Mestrado