Investigations on 10 MHz LGS and LGT crystal resonators
| Autor: | Serge Galliou, J.J. Boy, J.P. Romand, A. Assoud, Roger Bourquin, J. Imbaud |
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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), DGA contract number 04.34.033 |
| Jazyk: | angličtina |
| Rok vydání: | 2007 |
| Předmět: |
Materials science
Resonator Overtone Polishing Color 02 engineering and technology Comparison High quality 01 natural sciences Material Radius of curvature (optics) Crystal Optics Supplier Machining 0103 physical sciences Oscillator Langatate 010301 acoustics Quartz Langasite business.industry LGS 021001 nanoscience & nanotechnology [SPI.TRON]Engineering Sciences [physics]/Electronics LGT Q factor Defect 0210 nano-technology business |
| Zdroj: | Proceedings of Joint Meeting European Frequency and Time Forum-IEEE International Frequency Control Symposium Joint Meeting European Frequency and Time Forum-IEEE International Frequency Control Symposium Joint Meeting European Frequency and Time Forum-IEEE International Frequency Control Symposium, May 2007, Geneva, Switzerland. pp.711-714 |
| Popis: | International audience; Abstract— Materials in the LGT family are promising for designing bulk acoustic wave resonators with high quality factor. In our laboratory, we have manufactured a lot of plano-convex 10 MHz 5th overtone Y-cut resonators using LGS (langasite La3Ga5SiO14) and LGT (langatate La3Ga5.5Ta0.5O14) crystals. Our initial aim was to do noise measurements on these home-made resonators but problems occurred during manufacturing. It was the opportunity for further investigations. Indeed, we observed that the quality factor depends strongly on the energy trapping, the polishing method and the materials quality from one supplier to another. As for the quartz crystal, we have found that the material quality can be qualified by IR spectrometry whose resulting spectra exhibit absorption peaks more or less deep, linked to defects. These predominant criteria are not surprising but although they are nowadays quite well-defined in the case of quartz crystal resonators, they have to be defined again in the case of these LGS and LGT crystals. Then, a satisfying machining and polishing method has been first applied to elaborate high Q resonators. A comparison between different grades of LGS and LGT materials is established. In addition, LGT resonators are characterized by their motional parameters and frequency-temperature curves. Nevertheless, one of the main results is that the measured Q-f product is not the expected one. We present results of Q-factor versus radius of curvature and their comparison with the theoretical approach. It appears that an optimization should be performed. Right now the best resonator that we have made has got a Q-f product of 1.4 1013 on its 5th overtone (1.7 1013 on its 9th overtone). This result is slightly higher than the similar parameter obtained on a SC-cut quartz crystal resonator working at the same frequency. |
| Databáze: | OpenAIRE |
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