Resonance properties of shear-horizontal surface acoustic waves on Ca3TaGa3Si2O14 at room and high temperatures

• Published in: Japanese Journal of Applied Physics 2023-07, Vol.62 (SJ), p.SJ1022
• Main Authors: Suzuki, Ryoto, Suzuki, Masashi, Kakio, Shoji, Kimura, Noritoshi
• Format: Article
• Language: English
• Subjects: Acoustic properties; Acoustic resonance; CTGS; Elastic properties; Electrodes; Film thickness; Frequency shift; High temperature environments; Interdigital transducers; Resonance; SAW resonator; SH SAW; Surface acoustic waves; Thickness measurement; Zero temperature coefficient
• ISSN: 0021-4922; 1347-4065
• DOI: 10.35848/1347-4065/acb4fd

The resonance properties of shear-horizontal surface acoustic waves on Ca3TaGa3Si2O14 (CTGS) with Au or Al interdigital transducers (IDTs) were investigated. IDT-type resonators were fabricated on CTGS (0°, 134° or 155°, 90°) using Au- or Al-IDT, and the strong resonance properties and near-zero temperature coefficient of frequency (TCF) were measured at a certain electrode film thickness. From the measured and simulated results, an effective coupling factor of approximately 1.2% and zero TCF can be simultaneously obtained by using not only a high-density Au-IDT but also an Al-IDT and by adjusting the cut angle and electrode film thickness. Moreover, the resonance properties on Au-IDT/CTGS were evaluated at temperatures up to 570 °C. From the cut-angle dependences of the frequency shift calculated using the determined second-order temperature coefficients of the elastic constants, the potential for sensor applications that measure not only temperature but also pressure in such high-temperature environments can be expected.