Estimation of temperature dependence of C44 elastic constant in LiTaO3 single crystals
| Autor: | Gonzalez, Minerva, Bartasyte, Ausrine, Dulmet, Bernard, Edouard Guichardaz, Blandine, Henrot, Fabien, Bassignot, Florent, Herth, Etienne, Margueron, Samuel, Ballandras, Sylvain, Kajiyama, C, Bleyl, Ingo, Brice, J |
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| Přispěvatelé: | Franche-Comté Électronique Mécanique, Thermique et Optique - Sciences et Technologies (UMR 6174) (FEMTO-ST), Université de Technologie de Belfort-Montbeliard (UTBM)-Ecole Nationale Supérieure de Mécanique et des Microtechniques (ENSMM)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC)-Centre National de la Recherche Scientifique (CNRS), Frec'n'sys SASU (Frec'n'sys SASU), Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC) |
| Jazyk: | angličtina |
| Rok vydání: | 2015 |
| Předmět: | |
| Zdroj: | International Ultrasonics Symposium International Ultrasonics Symposium, Oct 2015, Taipei, Taiwan |
| Popis: | International audience; In this work, electromechanical coupling factor, K2, and Temperature Coefficient of Frequency (TCF) of Bulk Acoustic Wave (BAW) resonators based on high aspect ratio ridge structures in 42°Y-X LiTaO3 (LT) and Z-cut LT single crystals with different Li stoichiometries were studied experimentally, analytically and by combined finite element / boundary element analysis. Initially, analytical analysis was carried out to determine the contribution of different elastic constants in thickness field excitation of shear modes in high aspect ratio ridge structures. The analysis shows shear modes that are dependent on C44 in ridge resonators based on 42°Y-X and Z-cut LT crystals. However, the measured frequency response of such structures exhibited many spurious resonances, making difficult the direct extraction of acoustical parameters. A fitting procedure that allows taking into account several resonances occurring simultaneously in a restricted frequency range was used. Higher K2 and more positive temperature dependence of frequency were determined for ridge structures in nearly stoichiometric crystals compared to those of equivalent structures in congruent ones. |
| Databáze: | OpenAIRE |
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