Structural, microstructural, optical and electrical properties of (Pb,Ba,Sr)TiO3 films growth on conductive LaNiO3-coated LaAO3(100) and Pt/Ti/SiO2/Si substrates

• Published in: Materials letters Vol. 121; pp. 93 - 96
• Main Authors: Pontes, D.S.L., Capeli, R.A., Garzim, M.L., Pontes, F.M., Chiquito, A.J., Longo, E.
• Format: Journal Article
• Language: English
• Published: 15.04.2014
• Subjects: Barium strontium titanates; Dielectric constant; Dielectrics; Electrical properties; Electrodes; Permittivity; Silicon dioxide; Silicon substrates
• ISSN: 0167-577X
• DOI: 10.1016/j.matlet.2014.01.119

The ferroelectric and dielectric properties of lead barium strontium titanate (PBST) thin films are investigated on different bottom electrode and substrate such as Pt, LaNiO3 and Pt/Ti/SiO2/Si, LaAlO3(100), respectively. X-ray diffraction results indicate that the PBST and LaNiO3 films on LaAlO3(100) single crystal substrate are highly (100)-oriented whereas the PBST films on Pt/Ti/SiO2/Si are polycrystalline. The results indicate strong effects of bottom electrode on the dielectric permittivity and tunability of the PBST films. The dielectric permittivity and tunability for the highly (100)-oriented PBST films on LaNiO3/LaAlO3(100) structure were 1238% and 65%, respectively, at 100kHz, while PBST films prepared on Pt/Ti/SiO2/Si substrate, showed a dielectric permittivity of 520 and tunability of 47%, at 100kHz. A slight shift of the phase transition temperature to lower temperatures was observed for highly (100)-oriented films in comparison to the polycrystalline films. Electrical properties should depend strongly on orientation and bottom electrode, which is reflected in our experimental observations.