Lebrun L, Sebald G, Guiffard B, Richard C, Guyomar D, Pleska E
INSA, LGEF, Batiment Gustave FERRIE, 8 Rue de la Physique, 69621 Villeurbanne Cedex, France.
Ultrasonics. 2004 Apr;42(1-9):501-5. doi: 10.1016/j.ultras.2004.01.028.
Ferroelectric single crystals of PZN-PT and PMN-PT exhibit outstanding properties: high charge coefficient (dij), high coupling factor (kij) and high strain levels under DC fields. Besides, their mechanical quality factor is believed to be low. Their usefulness for non-resonant or large bandwidth transducers has therefore been previously investigated. However, few studies have been devoted to the dielectric and mechanical losses of single crystals and to their stability under high levels of excitations (electric fields, temperature and mechanical stress). A knowledge and understanding of such performances is needed to determine whether single crystals are suitable materials for power or resonant transducers. In this work, losses and non-linearity versus external excitations are investigated. Dielectric losses and mechanical losses are measured versus electric field for different compositions, orientations. The evolution of d33 and epsilonT33 are obtained versus electric field and temperature for the longitudinal mode. Strain and hysteresis versus sweep mode (up and down) are measured near the resonance frequency using a laser Doppler vibrometer.
PZN-PT和PMN-PT铁电单晶表现出优异的性能：高电荷系数（dij）、高耦合系数（kij）以及在直流电场下的高应变水平。此外，人们认为它们的机械品质因数较低。因此，此前已经对它们在非谐振或大带宽换能器中的应用进行了研究。然而，很少有研究致力于单晶的介电损耗和机械损耗以及它们在高激励水平（电场、温度和机械应力）下的稳定性。为了确定单晶是否是功率或谐振换能器的合适材料，需要了解和认识这些性能。在这项工作中，研究了损耗和非线性与外部激励的关系。针对不同的成分、取向，测量了介电损耗和机械损耗与电场的关系。获得了纵向模式下d33和εT33随电场和温度的变化情况。使用激光多普勒测振仪在共振频率附近测量了应变和滞后与扫描模式（向上和向下）的关系。
