PZT 50/50 nanocrystalline powders with tetragonal structure prepared via gel combustion route: Effect of heat treatment on phase and chemical compositions

Abstract

Comparative structural and thermal investigations of a process of formation of nanocrystalline lead zirconate titanate Pb(Zr0.50Ti0.50)O3 (PZT 50/50) powders, with a tetragonal structure, prepared via a gel combustion route under different thermal treatment conditions, were conducted. The thermal behaviour of a gel and an as-formed combustion product (powdered precursor) was studied using TGA/DTA techniques. The XRD study of the powdered precursor calcined at various temperatures, in combination with the TGA/DTA data, resulted in the establishment of the optimal temperature mode for obtaining a single-phase PZT 50/50 nanopowder. A possible mechanism for the formation of the PZT 50/50 phase during gel combustion has been proposed.Formation of a single-phase PZT powder with a given molar ratio of Pb/Zr/Ti = 1/0.5/0.5 was verified by XRD, μ-XRF and EDS methods. The results of XRD and FTIR spectroscopy indicated the tetragonal crystal structure of the PZT powder. The nanocrystalline nature of PZT 50/50 was confirmed by both XRD and SEM data. SEM studies revealed that the prepared nanopowders had a homogeneous, porous, coral-like microstructure with an average grain size in the range of 90–100 nm. According to the simultaneous thermal analysis (TGA/DSC) results, thermal stability of the PZT 50/50 nanopowder was observed up to 1000 °C. Local capacitance and the distribution of its values were measured on the surface of the PZT 50/50 coating, formed on Pt/Al2O3/Pt substrate using the screen printing technique, using scanning capacitance microscopy (SCM).