KNN/BNT composite lead-free films for high-frequency ultrasonic transducer applications

IEEE Trans Ultrason Ferroelectr Freq Control. 2011 Jan;58(1):249-54. doi: 10.1109/TUFFC.2011.1793.

Abstract

Lead-free K(0.5)Na(0.5)NbO(3)/Bi(0.5)Na(0.5)TiO(3) (KNN/ BNT) films have been fabricated by a composite sol-gel technique. Crystalline KNN fine powder was dispersed in the BNT precursor solution to form a composite slurry which was then spin-coated onto a platinum-buffered Si substrate. Repeated layering and vacuum infiltration were applied to produce 5-μm-thick dense composite film. By optimizing the sintering temperature, the films exhibited good dielectric and ferroelectric properties comparable to PZT films. A 193-MHz high-frequency ultrasonic transducer fabricated from this composite film showed a -6-dB bandwidth of approximately 34%. A tungsten wire phantom was imaged to demonstrate the capability of the transducer.

Publication types

  • Letter
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Ceramics / chemistry
  • Equipment Design
  • Metals / chemistry*
  • Phantoms, Imaging
  • Transducers*
  • Ultrasonography / instrumentation*
  • Ultrasonography / methods*

Substances

  • Metals