Piezoelectric and Dielectric Properties of LiNbO3, PMN-PT, and PZT-5A Materials at Cryogenic Temperatures

Abstract

The piezoelectric coecients dij , dielectric constant K ij , dielectric loss, creep and hysteresis were measured for 41 X-cut lithium niobate (LiNbO3), single crystal lead magnesium niobate-lead titanate (PMN-PT) and ceramic lead zirconium titanate (PZT-5A) transducers. The measurements were made between room temperature and 78 mK. The magnitude and temperature dependence of the three materials' properties can be understood in terms of intrinsic and extrinsic mechanisms in single crystals and ceramics. Several new features were observed, including a direct connection between creep and hysteresis, a unique region of negative creep in PMN-PT, and a surprisingly strong low-temperature dependence of d15 for PMN-PT and PZT, that extends well below 1 K. The strong low-temperature dependence of d15 PMN-PT and PZT suggests that there must be a wide range of small energy scales involved in domain wall motion. The hysteresis and creep in PMN-PT extend to temperatures below 10 K, which is consistent with weakly pinned domain walls. The dielectric loss does not show unusual behavior in the negative creep region of the temperature range, suggesting that the negative creep mechanism does not aect the behavior. In PZT, the hysteresis disappears below 30 K, as expected if its domain walls are pinned by grain boundaries. The implication for selecting the best material for positioning actuators that need large displacement involve d15. At cryogenic temperatures, one can use a LiNbO3 transducer/stack to achieve this. All three materials would be eective cryogenic ultrasonics sensors, but it would be challenging to use any of them as voltage sensors at frequencies below 1 kHz, since high input impedance would be needed. Given its nearly constant sensitivity for g15 and dielectric constant, LiNbO3 is probably the best sensor choice for precise measurements that cover a wide temperature range.