The effect of la concentration on the structural and electronic properties of tetragonal pzt using first principles calculation

The effect of Lanthanum (La) concentration on the structural and electronic properties of tetragonal Lead Zirconate Titanate, (PZT) were investigated in this study using first-principles calculation. Since lead (Pb) is recognised as a toxic substance with serious consequences for human health and the environment, La-doped PZT was selected to be examined. Lead-free elements have been considered potential substitute materials for ferroelectric components in PZT. This study aims to investigate and understand the structural and electronic properties of pure PZT. La was chosen as a dopant to study its effect on the electronic and structural PZT properties. First-principle calculations based on density functional theory (DFT) incorporated into the CASTEP software were used to accomplish the computations. Different exchange-correlation functional approximations, such as the Local Density Approximation (LDA-CAPZ) and the Generalised Gradient Approximation (GGA-PBE and GGA-PBEsol), were used to determine the geometry optimisation of ferroelectric phase materials. The lattice parameter and structure volume values calculated by GGA-PBE for PZT were the most precise. Additionally, the outcomes of tetragonal PZT were comparable to those of experiments. Hence, GGA-PBE was selected for La-doped PZT based on comparing the tetragonal PZT's lattice parameter with experiment data and selecting GGA-PBE as the most accurate. The best composition of La was 40%, with a lower band gap of 0.641 eV. By substituting or doping in a Pb-based system, these results will help experimentalists reduce the amount of lead they use, significantly advancing the field of green technology.