Structural, dielectric, ferroelectric and optical properties of PBCT, PBST and PCST complex thin films on LaNiO3 metallic conductive oxide layer coated Si substrates by the CSD technique

Author(s)

Pontes, D. S. L. ^[1] ; Chiquito, A. J. ^[2] ; Pontes, F. M. ^[3] ; Longo, E. ^{[1, 4]}

Affiliation

^[1] Univ Fed Sao Carlos, CDMF, LIEC, Dept Chem, BR-13565905 Sao Carlos, SP - Brazil

^[2] Univ Fed Sao Carlos, Dept Phys, NanO LaB, BR-13565905 Sao Carlos, SP - Brazil

^[3] Univ Estadual Paulista, UNESP, Dept Chem, BR-17033360 Bauru, SP - Brazil

^[4] Univ Estadual Paulista, UNESP, CDMF, LIEC, Inst Chem, Araraquara, SP - Brazil

• Document type: Journal article
• Source: Journal of Alloys and Compounds; v. 609, p. 33-39, OCT 5 2014.
• Web of Science Citations: 6

Abstract

Ferroelectric thin films and LaNiO3 (LNO) metallic conductive oxide thin films were prepared by a chemical solution deposition (CSD) method. PBCT60, PBST60 and PCST60 ferroelectric thin films were grown on different structures such as LNO/Si and single-crystalline quartz SiO2 (X-cut) substrates. The LNO layer acts as the bottom electrode for the electrical measurements. X-ray diffraction (XRD) analysis shows that LNO thin films on Si substrates and PBCT60, PBST60 and PCST60 thin films on LNO/Si structures are poly-crystalline with a moderate (110)-texture and a complete perovskite phase. LNO, PBCT60, PBST60 and PCST60 thin films have a continuous, dense and homogenous microstructure with a grain size on the order of 50-80 nm. Electrical resistivity-dependence temperature data confirm that LNO thin films display a good metallic character over a wide large range of temperatures. Optical characteristics of PBCT60, PBST60 and PCST60 thin films have also been investigated using ultraviolet-visible (UV-vis) spectroscopy in the wavelength range of 200-1100 nm. Ferroelectric thin films show a direct allowed optical transition with optical band gap values on the of order of 3.54, 3.66 and 3.89 eV for PBCT60, PCST60 and PBST60 thin films deposited on a SiO2 substrate, respectively. Good dielectric and ferroelectric properties are reported for ferroelectric thin films deposited on the LNO layer as bottom electrodes. Au/PBCT60/LNO/Si, Au/PBST60/LNO/Si and Au/PCST60/LNO/Si multilayer structures show a hysteresis loop with remnant polarization, P-r, of 9.6, 6.6 and 4.2 mu C/cm(2) at an applied voltage of 6 V for PBCT60, PBST60 and PCST60 thin films, respectively. (C) 2014 Elsevier B.V. All rights reserved. (AU)

• FAPESP's process: 11/20536-7 - Multifunctional ferroelectric materials: studies of optical, electrical and photoluminescent properties
• Grantee: Debora da Silva Lima Pontes
• Support type: Scholarships in Brazil - Post-Doctorate
• FAPESP's process: 13/07296-2 - CDMF - Center for the Development of Functional Materials
• Grantee: Elson Longo da Silva
• Support type: Research Grants - Research, Innovation and Dissemination Centers - RIDC