Stoichiometric Lithium Niobate Crystals: Towards Identifiable Wireless Surface Acoustic Wave Sensors Operable up to 600 °C

Jérémy Streque (1) , Thierry Aubert (2) , Ninel Kokanyan (2) , Florian Bartoli (2, 1) , Amine Taguett (2) , Vincent Polewczyk (1) , Edvard Kokanyan (3) , Sami Hage-Ali (1) , Pascal Boulet (1) , Omar Elmazria (1)

1 IJL - Institut Jean Lamour
2 LMOPS - Laboratoire Matériaux Optiques, Photonique et Systèmes
3 IPR NAS RA - Institute for Physical Research of National Academy of Sciences of Armenia

Wireless surface acoustic wave (SAW) sensors constitute a promising solution to some unsolved industrial sensing issues taking place at high temperatures. Currently, this technology enables wireless measurements up to 600-700°C at best. However, the applicability of such sensors remains incomplete since they do not allow identification above 400°C. The latter would require the use of a piezoelectric substrate providing a large electromechanical coupling coefficient K 2 , while being stable at high temperature. In this letter, we investigate the potentiality of stoichiometric lithium niobate (sLN) crystals for such purpose. Raman spectroscopy and X-ray diffraction attest that sLN crystals withstand high temperatures up to 800°C, at least for several days. In situ measurements of sLN-based SAW resonators conducted up to 600°C show that the K 2 of these crystals remains high and stable throughout the whole experiment, which is very promising for the future achievement of identifiable wireless high-temperature SAW sensors.

Mots clés: High-temperature sensors; Microsensors; Stoichiometric lithium niobate; Surface acoustic waves

Domaines: Science des matériaux [cond-mat.mtrl-sci]; Acoustique [physics.class-ph]; Micro et nanotechnologies/Microélectronique

Jérémy Streque, Thierry Aubert, Ninel Kokanyan, Florian Bartoli, Amine Taguett, et al.. Stoichiometric Lithium Niobate Crystals: Towards Identifiable Wireless Surface Acoustic Wave Sensors Operable up to 600 °C. IEEE Sensors Letters, 2019, 3 (4), pp.1-4. ⟨10.1109/LSENS.2019.2908691⟩. ⟨hal-02114799⟩