Temperature compensated cuts in LGT crystal microresonators using length extensional mode

2009 IEEE International Ultrasonics Symposium

Bigler

et al. 2009

Self Cite

Scanning microdeformation microscopy (SMM) is a near field microscopy in the mesoscopic domain. Such a microscope has become an alternative to the high resolution acoustic microscope that operates at very high frequencies. SMM is based on a vibrating contact tip and piezoelectric detection. The lateral resolution is essentially related to the tip diameter. Classically, the SMM sensor is obtained by a complex mounting process. The tip is glued on a Si cantilever driven by a piezoelectric ceramic. Piezoelectric crystal is an alternative to get a monolithic vibrating cantilever. Quartz crystal, which is the most often used piezoelectric material, can be advantageously replaced by Langasite crystal because of its higher piezoelectric coefficients and its better temperature behaviour.

Section: Principle Of the Scanning Microdeformation Microscopymentioning

confidence: 95%

Resonant LGS microsensor for scanning microdeformation microscopy

2009 IEEE International Ultrasonics Symposium

Bigler

et al. 2009

Self Cite

“…LGT length-extension resonators [3][4][5][6]. Consequently LGS crystal could be used to replace quartz crystal in several applications.…”

Section: Lgs Andmentioning

confidence: 99%

Chemically etched resonant LGS microsensors

Medeira

2010 IEEE International Frequency Control Symposium

et al. 2010

Self Cite

Materials like langasite (LGS), langatate (LGT) or gallium orthophosphate (GaPO 4 ) crystals have higher piezoelectric coefficients and also have a better hightemperature behaviour than quartz crystal. Thus they are worth being considered as a replacement for quartz in applications such as oscillators, piezoelectric accelerometers, microbalances or clocks. Length-extension resonators have already been manufactured using quartz crystal in order to get atomicallyresolved imaging by frequency-modulation atomic force microscopy. The goal of this study is to obtain better results with langasite. It has been shown that LGS-crystal microsensors should have a sensitivity three times better than quartz crystal ones. This fact added to the existence of temperaturecompensated cuts for the extensional mode of vibration is of prime importance for applications such as microcantilevers for frequency-modulation atomic force microscopes. This paper focuses on the fabrication of Langasite resonators with different cut angles around the temperature-compensated cuts both in length-extension and flexure mode.

“…However, materials such as langasite (lGs), langatate (lGT), and gallium orthophosphate (GaPo 4 ) which belong to the same class of crystals as quartz (32) are more piezoelectric than quartz crystal and they have better temperature behavior. It has been shown that temperature-compensated cuts exist at room temperature for GaPo 4 , lGs, and lGT lErs [8]- [11]. Thanks to this result, lGs crystal, whose chemical composition is la 3 Ga 5 sio 14 , could be used to replace quartz crystal in several applications, especially near field microscopy.…”

mentioning

confidence: 94%

Langasite as a piezoelectric material for near-field microscopy resonant cantilevers

IEEE Trans. Ultrason., Ferroelect., Freq. Contr.

Leblois

et al. 2010

Quartz length-extension resonators have already been used to obtain atomically-resolved images by frequency-modulation atomic force microscopy. Other piezoelectric materials such as gallium orthophosphate (GaPO(4)), langatate (LGT), and langasite (LGS) could be appropriate for this application. In this paper, the advantages of langasite crystal are presented and the fabrication of similar microsensors in langasite temperature-compensated cuts by chemical etching is proved. A monolithic length extension resonator, with a tip at its end, is obtained which constitutes a real advantage in regard to the existing quartz devices.