S.N.Bose National Centre For Basic Sciences, India
Title: Evaluation of sputtered PZT thin films on Ti-substrates upon re-crystallization with a thin Pb-overcoat
Biography: Ankita ghatak
Processing of thin lead zirconate titanate (PZT) films on metallic substrates has several advantages such as high frequency operation, low electrical series resistance, low dielectric loss and potential for embedded capacitor systems. As a suitable metal support for PZT films, titanium (Ti) seems to be the most natural choice as it posses high melting point, the thermal expansion coefficient of Ti matches closely to that of PZT and permits good adhesion with low reactivity. However, ferroelectric and piezoelectric responses of PZT films on Ti substrates are found to be not that encouraging. Presence of a non-ferroelectric pyrochlore/ fluorite (Py/Fl) phase on the surface of the PZT film is believed to be the primary cause for poor electrical performance.
In this work, effect of re-crystallization of PZT films with a thin Pb-overcoat has been investigated though structural, morphological, compositional and electrical studies. Sputter deposited PZT thin films on Ti-substrates are found to contain a Pb-deficient and Zr-enriched Py/Fl phase of type Pb2(Zr,Ti)2O6 on the surface of the PZT film. Re-crystallization of these PZT films with a thin lead (Pb) overcoat improves the degree of crystallization, morphology and dielectric/ ferroelectric properties of the films by converting the top Pb-lean and Zr-rich Py/Fl phase into perovskite phase. Structural changes that occur in PZT films upon re-crystallization with a Pb-overcoat have been correlated with ferroelectric characteristics of the PZT films
Recent Publications :
- Ghatak A, Roy Moulik S, Ghosh B(2016) Pulsed laser assisted growth of aligned nanowires of WO3 and their microstructural analysis. RSC ADVANCES 6:31705-31716.
- Roy Moulik S, Ghatak A, Ghosh B (2016) Study of surface chemistry and microstructure of TiO2 nanostructures on Pt/Si wafers and FTO glass substrates: a comparative approach. Surface Science 651:175-181.
- Datta S, Ghatak A, Ghosh B (2016) Controlled hydrothermal growth of single crystalline nanowires and related nanostructures of perovskite oxide manganites (La1-xAxMnO3) with adaptable stoichiometry and morphology. Journal of Material Science 51:9679-9695.
- H. Debnath G, Chakraborty A, Ghatak A, Mandal M, Mukherjee P (2015) Controlled Terbium(III) Luminescence in Zinc Sulfide Nanoparticles: An Assessment of Competitive Photophysical Processes. Journal of Physical Chemistry C 119:24132-24141.
- Ghatak A, Debnath G, Mandal M, Mukherjee P (2015)Lanthanide Cation Induced Tuning of Surface Capping Properties in Zinc Sulfide Nanoparticles: An Infrared Absorption Study. RSC ADVANCES 5:32920-32932.