Computational Study of the Piezoelectric Performance of Barium Titanate Crystals in the Presence of Vacancy Defect: Molecular Dynamics Approach

Certain materials (ceramics and polymers) are capable of converting mechanical energy into electrical energy via the piezoelectric effect. The piezoelectric effect is fundamentally associated with momentary electric dipoles that occur in solids. The external surface may be borne directly by molecular groups or excited in the crystal lattice by an asymmetric peripheral charge. Using molecular dynamics simulation, the current study examined the effect of atomic vacancies on the piezoelectric properties of barium titanate crystals. For this reason, the diffusion coefficient, ferroelectric hysteresis loop, piezoelectric hysteresis loop, and strain–polarization curve were all examined. Increasing atomic vacancy to 20% increased the maximum (Max) value of residual strain and polarization in the simulated structure, according to the results. Optimal orientation, appropriate displacement of charged atoms, and the formation of effective dipoles all contributed to this. Consequently, the ferroelectric and piezoelectric properties of the structure were enhanced. In the sample containing 20% atomic vacancies, atomic movement was also extremely high. As opposed to the sample containing 30% atomic vacancy, however, its structure was less porous. Hence, when 20% atomic vacancy was present, the structure exhibited its most optimal polarization.