KNN/BNT composite lead-free films for high-frequency ultrasonic transducer applications.
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.
Sien Ting
ST
Lau
Hong Fen
HF
Ji
Xiang
X
Li
Wei
W
Ren
Qifa
Q
Zhou
K Kirk
KK
Shung
D002516:Ceramics / Q000737:chemistry; D004867:Equipment Design; D008670:Metals / Q000737:chemistry*; D019047:Phantoms, Imaging; D014159:Transducers; D014463:Ultrasonography / Q000295:instrumentation* / Q000379:methods*
D008670:Metals
IEEE Trans Ultrason Ferroelectr Freq Control. 2001 Jan;48(1):299-306
11367799
Appl Phys Lett. 2009 Mar 9;94(10):102901
19529788
Ophthalmology. 2004 Jul;111(7):1344-51
15234135
Ultrasound Med Biol. 1995;21(1):79-88
7754581
J Am Ceram Soc. 2009 May 8;92(6):1276-1279
20376196
Ultrasonics. 2006 Dec 22;44 Suppl 1:e711-5
16793087
IEEE Trans Ultrason Ferroelectr Freq Control. 2003 Nov;50(11):1548-57
14682638
IEEE Trans Ultrason Ferroelectr Freq Control. 2006 Aug;53(8):1524-33
16921905