GRUBER: Small-scale mechanical characterization of LiTaO3 and LiNbO3 single crystals for SAW filters
Channel: Chair of Structural and Functional Ceramics
Date: 2022-07-18

[Title]
Small-scale mechanical characterization of LiTaO3 and LiNbO3 single crystals for SAW filters

[Authors]
Manuel GRUBER
Daniel KIENER
Peter SUPANCIC
Raul BERMEJO

[Event]
97th DKG Annual Meeting - Ceramics 2022
Tuesday, 8th March 2022

[Abstract]
The requirements on new materials used in mobile communications are driven by the demand for higher data transfer rates. Single crystalline piezoelectric materials such as LiTaO3 and LiNbO3 have thereby qualified as substrates for precise and efficient frequency filters and are consequently employed in the newest 5G mobile communication network standards. Crystal growth in specific orientations are usually pursued to ensure optimized functional properties. The question rises whether such orientations may withstand thermo-mechanical loading during qualification and/or service. In this work, biaxial strength measurements along with in-situ SEM fracture toughness experiments were performed on miniaturized specimens to investigate the mechanical performance of LiTaO3 and LiNbO3 materials. Atomistic modelling calculations supported the experimental results and provided recommendations for crystal orientations with enhanced mechanical properties. In addition, nanoindentation experiments and preliminary in-situ TEM tests showed onset of plastic deformation for specific loading scenarios. These findings at the micro-scale may be utilized in the fabrication of LiTaO3 and LiNbO3 materials of particular orientations with optimized structural and functional properties.