Analyzing surface acoustic wave characteristics through first-principles computational methods

Abstract

Surface acoustic wave (SAW) characteristics were analyzed through first-principles calculations utilizing density functional theory. This study computed and compared the elastic constants, piezoelectric constants, dielectric constants, and densities of LiTaO3 and LiNbO3, which are standard materials for SAW filters, against empirical values. The velocities of SAWs and the electromechanical coupling coefficients for both Rayleigh and leaky waves were also determined, demonstrating the method’s sufficient precision for assessing SAW attributes. In addition, this approach was extended to the nitride perovskite LaWN3, evaluating its SAW characteristics. LaWN3 is projected to exhibit an electromechanical coupling coefficient comparable to that of LiTaO3 and LiNbO3, indicating its potential as a novel material for SAW filter applications.