Table 2.

Physical constants of AlN, Sapphire and Platinum.

Material	Symbol	AlN [33]	Sapphire [34]	Platinum [35]
Density (kg/m3)	$\rho$	3260	3980	21,450
Elastic constants (GPa)	$C_{11}$	345	497	348.0
	$C_{12}$	125	164	241.74
	$C_{13}$	120	111	-
	$C_{14}$	-	−23.5	-
	$C_{33}$	395	498	-
	$C_{44}$	118	147	-
Piezoelectric constants (C/m2)	$e_{15}$	−0.48	-	-
	$e_{31}$	−0.58	-	-
	$e_{33}$	1.55	-	-
Dielectric constants (10−11 F/m)	${\epsilon }_{11}$	8.2	2.25	-
	${\epsilon }_{33}$	9.5	10.2	-