Skip to Main Content
Mass density, dielectric, elastic, and piezoelectric constants of bulk GaN crystal were determined. Mass density was obtained from the measured ratio of mass to volume of a cuboid. The dielectric constants were determined from the measured capacitances of an interdigital transducer (IDT) deposited on a Z-cut plate and from a parallel plate capacitor fabricated from this plate. The elastic and piezoelectric constants were determined by comparing the measured and calculated SAW velocities and electromechanical coupling coefficients on the Z- and X-cut plates. The following new constants were obtained: mass density p = 5986 kg/m3; relative dielectric constants (at constant strain S) ε11S/ε0 = 8.6 and ε11S/ε0 = 10.5, where ε0 is a dielectric constant of free space; elastic constants (at constant electric field E) C11E = 349.7, C12E = 128.1, C13E = 129.4, C33E = 430.3, and C44E = 96.5 GPa; and piezoelectric constants e33 = 0.84, e31 = -0.47, and e15 = -0.41 C/m2.