中国物理B ›› 2009, Vol. 18 ›› Issue (2): 795-802.doi: 10.1088/1674-1056/18/2/064
张超1, 刘岩1, 王文炎2, 张志甜2, 冯冠平3
Wang Wen-Yan(王文炎)a), Zhang Chao(张超)b)†, Zhang Zhi-Tian(张志甜)a), Liu Yan(刘岩)b), and Feng Guan-Ping(冯冠平)a)b)
摘要: LiNbO3 has been found attractive for lateral field excitation (LFE) applications due to its high piezoelectric coupling. In this paper, bulk acoustic wave propagation properties for LiNbO3 single crystal excited by a lateral electric field have been investigated using the extended Christoffel--Bechmann method. It is found that the LFE piezoelectric coupling factor for c mode reaches its maximum value of 95.46% when ψ = 0° for both (yxl)-58° and (yxwl)± 60°/58° LiNbO3. The acoustic wave phase velocity of c mode TSM (thickness shear mode) changes from 3456m/s to 3983 m/s as a function of ψ. Here ψ represents the angle between the lateral electric field and the crystallographic X-axis in the substrate major surface. A 5MHz LFE device of (yxl)-58° LiNbO3 with ψ=0° was designed and tested in air. A major resonance peak was observed with the motional resistance as low as 17Ω and the Q-factor value up to 10353. The test result is well in agreement with the theoretical analysis, and suggests that the LFE LiNbO3 device can be a good platform for high performance resonator or sensor applications.
中图分类号: (Acoustoelectric effects and surface acoustic waves (SAW) in piezoelectrics)