Temperature dependence of the piezoelectric shear coefficient of PMN-PT, LiNbO3 and PZT transducers

• Author / Creator

  Bukhari, Syed Asad Manzoor

• Piezoelectric transducers are widely used as sensitive detectors of stress and to generate nanometer scale displacements. However, their piezoelectric coefficients often decrease substantially at cryogenic temperatures, limiting their performance in, e.g., low temperature STMs (scanning tunneling microscopes), biomedical imaging and space applications. It’s important these days to understand the behavior of sensors and actuators at low temperatures because of their use at these temperatures. We have recently used PZT (lead zirconate titanate) shear transducers to measure the elastic modulus of solid 4He at very low strains and to plastically deform the helium at high strains. From our elastic measurements, we inferred a shear piezoelectric coefficient d15 = 1.0× 10^(-10) m/V below 1 K. This is about 6 times smaller than the room temperature value for PZT and comparable to d15 for single crystal LiNbO3 transducers (7.0×10^(-11) m/V). We have now developed a capacitive technique and have directly measured the temperature dependence of d15 for ceramic (PZT) and single crystal LiNbO3 and PMN-PT (lead magnesium niobium-lead titanate) shear transducers. PMN-PT has an extremely large d15 at room temperature (4.0×10^(-9) m/V) but it decreases rapidly below 100K. LiNbO3 has the smallest room temperature d15, but it is nearly temperature independent. At 4 K, these three types of transducers d15 have similar piezoelectric shear coefficients.

• Subjects / Keywords

  • PZT, PMN-PT, LiNbO3 transducers
  • Temperature dependence of d15
  • Piezoelectricity at cryogenic temperatures
  • Piezoelectic coefficient
  • Measuring d15 at cryogenic temperatures
  • Temperature dependence of piezoelectric

• Graduation date

  Spring 2014

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/R36M33C07

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.