First-principle study the piezoelectricity of a new quartz-type crystal BaZnO2

The piezoelectric properties of a new quartz-type crystal BaZnO2 (general formula ABO2) was studied by first-principle calculation. The calculated lattice parameters were a = 5.890 إ, c = 6.781 إ by LDA, which was consistent with experimental value well. The predicted piezoelectric strain coefficient was d11 = 11.84 pC/N and the electromechanical coupling coefficients k11 was 35.7%, both of which were much higher than other quartz-type crystals, indicating bright prospects in high-piezoelectric application. Finally, the origin of large piezoelectricity of BaZnO2 was discussed by decomposition the piezoelectric stress tensor eij compared with SiO2.