Vol.:(0123456789) 1 3 Journal of Thermal Analysis and Calorimetry https://doi.org/10.1007/s10973-020-09439-8 Thermal analysis of the crystallization kinetics of lead zirconate titanate powders prepared via sol–gel route Radhouane Bel‑Hadj‑Tahar 1,2  · Mohamed Abboud 1  · Mouna Bouzitoun 2 Received: 10 February 2019 / Accepted: 11 February 2020 © Akadémiai Kiadó, Budapest, Hungary 2020 Abstract The crystallization evolution of lead zirconate titanate (PZT) powders processed from two organic gel systems with nominal composition was investigated. The crystallization of the perovskite PZT form initiated as the calcining temperature reached 400 °C. The formation of PbO phase constituted seeding grains for PZT crystallization at such low temperature. The forma- tion of lead-defcient fuorite or pyrochlore phases was completely avoided under judicious processing conditions. TGA/ DTA analysis was carried out to evaluate the activation energy associated with the perovskite phase formation. The kinetic parameters of the PZT crystallization toward perovskite formation were followed by employing Kissinger and JMAK isocon- versional kinetic models. The results revealed that the crystallization mechanism is related to the powder precursor system. The value of the activation energy for the perovskite formation was about 77 kJ mol −1 irrespective of the precursor system when the Kissinger model was applied. Keywords Thermal analysis · Crystallization kinetics · Lead zirconate titanate · Sol–gel Introduction Lead zirconate titanates are of great technological impor- tance due to their excellent ferroelectric and piezoelectric properties. PZT-based materials are commonly applied in electronics and microelectronics. The best piezo- electric properties are associated with the morphotropic composition. The synthesis of PZT powder of high quality is essential to develop superior piezoelectric PZT ceramics. PZT pow- ders are mostly prepared through conventional solid-state reaction starting from their individual metal oxides. Mate- rials synthesized via this technique are often very fragile and porous to be easily polarized [1]. Chemical processing routes are usually used to maintain the stoichiometry and to lower the crystallization temperature and particle size in order to produce highly dense product. The fabrication of high-quality PZT powders at low tem- perature is highly required. The crystallization of the PZT perovskite phase is compelled by nucleation, which needs considerable activation energy [2]. The kinetic analysis of the thermal decomposition route is an essential step to com- prehend how the material behaves under diferent function- ing conditions. In addition, the determination of the kinetic mechanism helps optimizing the processing parameters. The kinetics of sol–gel reactions has been explored by sev- eral groups. Fernandes et al. [3] have found that the rate of PZT crystallization is directly related to the decline of the amorphous phase content, which is in turn afected by the oxidation of the carbonaceous mass. Merckle et al. [4] investigated isothermal and non-isothermal crystallization of PZT (45/55) sample processed by the sol–gel method using 2-methoxyethanol as the solvent. They reported an apparent activation energy around 300 kJ mol −1 for the pyrochlore-to- perovskite conversion and an Avrami exponent of 1. This study aims to investigate the structural evolu- tion and the crystallization kinetics in order to determine the most plausible growth mechanism of the sol–gel- processed PZT nanopowders. Two sol precursor systems will be explored. The main objective of this work is to investigate the crystallization behavior of PZT powder and to determine important kinetic parameters related * Radhouane Bel-Hadj-Tahar radhouanebelhadjtahar@gmail.com 1 Department of Chemistry, College of Science, King Khalid University, Abha 61413, Saudi Arabia 2 Photovoltaic Laboratory, Research and Technology Center of Energy, Borj-Cedria Science and Technology Park, BP 95, 2050 Hammam-Lif, Tunisia