Dielectric and Piezoelectric Properties of PZT Composite Thick Films with Variable Solution to Powder Ratios
Abstract:The use of PZT films in sliver-mode high-frequency ultrasonic transducers applications requires thick, dense, and crack-free films with excellent piezoelectric and dielectric properties. In this work, PZT composite solutions were used to deposit PZT films >10 m in thickness. It was found that the functional properties depend strongly on the mass ratio of PZT sol–gel solution to PZT powder in the composite solution. Both the remanent polarization, Pr, and transverse piezoelectric coefficient, e31,f, increase with increasing proportion of the sol–gel solution in the precursor. Films prepared using a solution-to-powder mass ratio of 0.5 have a remanent polarization of 8 C/cm2, a dielectric constant of 450 (at 1 kHz), and e31,f=−2.8 C/m2. Increasing the solution-to-powder mass ratio to 6, the films were found to have remanent polarizations as large as 37 C/cm2, a dielectric constant of 1250 (at 1 kHz) and e31,f=−5.8 C/m2.
Document Type: Research Article
Affiliations: 1: Department of Biomedical Engineering, NIH Transducer Resource Center University of Southern California, Los Angeles, California 90089 2: Department of Materials Science and Engineering, Materials Research Institute The Pennsylvania State University, University Park, Pennsylvania 16802 3: Chemat Technology Inc., Northridge, California 91324
Publication date: June 1, 2009