In:
The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 101, No. 5_Supplement ( 1997-05-01), p. 3094-3094
Kurzfassung:
Relaxor ferroelectric single crystals of Pb(Zn1/3Nb2/3)O3 (PZN), Pb(Mg1/3Nb2/3)O3 (PMN) and their solid solutions with normal ferroelectric PbTiO3 (PT) were investigated for ultrasonic transducer applications. Longitudinal coupling coefficients (k33) as high as 94% and dielectric constants (K3T) in the range of 3500–6000 were achieved with low dielectric loss ( & lt;1%) using 〈001〉 oriented rhombohedral crystals of (1−x)PZN-xPT and (1−y)PMN-yPT, where x & lt;0.09 and y & lt;0.35. Dicing direction as well as poling direction was critical for high coupling under laterally clamped conditions. Dicing parallel to the (001) yields 90% of laterally clamped coupling (kbar) out of 94% longitudinal coupling (k33) for PZN-8%PT. Thickness coupling (kT) as high as 64% and low dielectric constant (K3T) & lt;600 with low loss ( & lt;1%) could be achieved using tetragonal crystals of (1−x)PZN-xPT and (1−y)PMN-yPT, where x & gt;0.1 and y & gt;0.4. The performance gains associated with these ultra-high coupling coefficients and range of dielectric constants are evident in relations to broader bandwidth and electrical impedance matching. Using the KLM model, a pulse/echo response simulated a bandwidth of ∼124% for a subdiced array element with a center frequency of 10 MHz. An optimized array design of the same geometry constructed of PZT 5H displayed 87% bandwidth. [Work supported by ONR, DARPA.]
Materialart:
Online-Ressource
ISSN:
0001-4966
,
1520-8524
Sprache:
Englisch
Verlag:
Acoustical Society of America (ASA)
Publikationsdatum:
1997
ZDB Id:
1461063-2
