“…Nevertheless, the application of quartz is limited to a maximum tempera-ture of 450 • C due to strongly increasing acoustic loss (Cernosek et al, 1998;Fritze, 2011a). Alternatively, piezoelectric materials like langasite (La 3 Ga 5 SiO 14 , LGS) or catangasite (Ca 3 TaGa 3 Si 2 O 14 , CTGS) enable the operation at fairly high temperatures, even above 1000 • C (Yu et al, 2016;Zu et al, 2016;Shah and Saha, 2021;Fritze, 2011b;Suhak et al, 2018;Sauerbrey, 1964;Seh et al, 2007).…”