“…The Chalcogenide family crystals (Tl 3 VS 4 and Tl 3 TaSe 4 [7]) belonging to the cubic class 43m and possessing both zero temperature coefficients and strong piezoelectric coupling, are examined. In spite of their very large potential interest, especially for moderate frequency and large bandwidth, such ternary thallium Chalcogenides Tl 3 TaSe 4 are not commercially available, probably due to their mechanical softness and fabrication difficulties.…”