Theoretical Predictions on the Effective Piezoelectric Coefficients of Wurtzite LaN Compound from DFT and DFPT Calculations

Abstract

To study the structural, elastic, piezoelectric and dielectric properties of wurtzite (LaN), we have used the ab initio total-energy pseudo-potential plane-wave method (PP-PW) based on density functional theory (DFT) and density functional perturbation theory (DFPT), which performed with Generalized gradient approximation (GGA) as well as local density approximation (LDA). The calculations of piezoelectric constants by mean of linear-response calculations second derivative with respect to a strain and a modification of the electric field.The compound shows a large effective piezoelectric constant (𝑑 33 ) being in the order of 66.96, and 77.260 pc/N with (GGA), and (LDA) calculations, respectively. The dielectric properties and electromechanical coupling coefficients have been calculated. Finally, our piezoelectric findings indicate that the LaN compound has a high effective piezoelectric constant value (𝑑 33 ) which allows it to be in direct competitor of zinc oxide ZnO and aluminum nitride AIN. We hope that our findings provide guidelines for the experimental realization and further research of high-performance materials appropriate for applications in different fields of study, such as biomedical engineering.