Electro-elastic characterization of Ca3TaGa3Si2O14 crystals for lateral-field-excitation acoustic wave sensing applications
The Ca 3 TaGa 3 Si 2 O 14 (CTGS) crystals with ordered structure are promising for piezoelectric sensing applications. In this work, the electro-elastic constants of CTGS crystals were determined taking advantage of impedance and pulse-echo methods. The relative dielectric permittivities ε 11 T /ε 0 and ε 33 T /ε 0 are 17.5 and 21.8, the elastic stiffness constants c 11 E , c 12 E , c 13 E , c 14 E , c 33 E , c 44 E and c 66 E are 15.63, 7.52, 8.55, 0.05, 22.51, 4.15 and 4.06 x 10 10 N/m 2 , while the piezoelectric coefficients d 11 and d 14 are 4.17 and −13.7 pC/N, respectively. In addition, the properties of lateral-field-excitation (LFE) acoustic wave were studied, where crystal cut with pure-LFE was designed and LFE acoustic wave prototype was fabricated. The mechanical quality factor Q m for CTGS based pure-LFE device in distilled water was obtained to be 1400, nearly two times that of La 3 Ga 5 SiO 14 based device, potential for sensing applications in liquid-phase environment.