Ab initio studies on phonon, dielectric, and piezoelectric responses in perovskite‐like bismuth aluminate

Ab initio method was used to explore the phonon, dielectric, and piezoelectric responses mechanism of the R3c phase BiAlO3 with rhombohedral structure by the generalized gradient approximation (GGA) of density function theory (DFT) and density functional perturbation theory (DFPT) using the plane wave (PAW) method of VASP code. The lattice parameters calculated from the stability of the structure are consistent with the existing experimental data. The micromechanism of dielectric and piezoelectric response was explored. Through the analysis and research, it can be seen that the large values of dielectric element ε11 and piezoelectric element e26 are basically due to low‐frequency infrared (IR) active phonons (ωλ = 1.561 and 1.962 THz) with E irreducible representation.