According to surface transient excitation theory of elastic wave for piezoelectric crystal,in the surface of a piezoelectric crystal can exist acoustical high velocity head wave except the general surface acoustic wav...According to surface transient excitation theory of elastic wave for piezoelectric crystal,in the surface of a piezoelectric crystal can exist acoustical high velocity head wave except the general surface acoustic wave(SAW).Such a mode is to propagate with the group velocity of the longitudinal bulk wave along the crystal surface.For ST quartz its value is 5.744×10^(3)m/s,which agrees with our experiments.The fact that the longitudinal head wave mode has a high propagation velocity offerspotential applications for high frequency SAW devices.展开更多
High-quality and high-resistivity GaN films were grown on (0001) sapphire face by metal-organic vapour phase epitaxy. To measure the surface acoustic wave properties accurately, we deposited metallized interdigital tr...High-quality and high-resistivity GaN films were grown on (0001) sapphire face by metal-organic vapour phase epitaxy. To measure the surface acoustic wave properties accurately, we deposited metallized interdigital trans ducers on the GaN surface. The acoustic surface wave velocity and electromechanical coupling coefficient were measured, respectively, to be 5667m/s and 1.9% by the pulse method.展开更多
基金Supported by National Natural Science Foundation of China under Grant No.19571063.
文摘According to surface transient excitation theory of elastic wave for piezoelectric crystal,in the surface of a piezoelectric crystal can exist acoustical high velocity head wave except the general surface acoustic wave(SAW).Such a mode is to propagate with the group velocity of the longitudinal bulk wave along the crystal surface.For ST quartz its value is 5.744×10^(3)m/s,which agrees with our experiments.The fact that the longitudinal head wave mode has a high propagation velocity offerspotential applications for high frequency SAW devices.
基金Supported by the National Natural Science Foundation of China under Grant No.60086001the Special Funds for the Major State Basic Research Project of China under Grant No.G20000683.
文摘High-quality and high-resistivity GaN films were grown on (0001) sapphire face by metal-organic vapour phase epitaxy. To measure the surface acoustic wave properties accurately, we deposited metallized interdigital trans ducers on the GaN surface. The acoustic surface wave velocity and electromechanical coupling coefficient were measured, respectively, to be 5667m/s and 1.9% by the pulse method.
