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Since Pb(ZrxTi1-x)O3 (PZT) piezoelectric ceramics was
synthesis by solidstate reaction of PbZrO3 and PbTiO3
precursors, vast amount of work was carriedout of study and to
develop the related piezoelectric properties and application .
Used as mechanical vibration type of transducer, piezoelectric
ceramic required hgih mechanical quality factor (Qm) in order to
minimize the self-heating problem during operation and to assure
better component life. In this study, the influence of doping
amount and dopant species among the sintering profile on the
piezoelectric properties of Pb(Zn1/3Nb2/3)O3-PbZrO3-PbTiO3 (PZN-
PZ-PT(37.5/28/34.5)), which was obtained via the mixed oxide
synthesis route, was systematicallly evaluated. The aim of this
study is to improve better electrical properties by achieving
higher mechanical quality factor (Qm) and radial
electromechanical coupling factor (kp) and lower dissipation
factor (tand) to meet the requirements of piezoelectric
transducers. Results indicate that the opitmal sintering
condition was 1200oC/1~3hr forPZN-PZ-PT-based piezoelectric
ceramics, of which radial electromechanical coupling factor (kp=
0.58~0.62) and piezoelectric strain constant (d33 = 398~428 pC/
N) were achieved with addition of 1~3 mol% SnO2. Such electric
propertiesare appropriate for piezoelectric actuator
application. With addong MnO2, thesintered PZN-PZ-PT showed
enhanced electrical properties including Qm=1200~1500, kp=0.53
~0.56, e33=1700, tand=0.5%, d33=280~320pC/N, with gives rise to
Curietemperature (Tc) ranged in the neighborhood of 280~320oC
and was demonstrated tobe suitable for vibration type of
transducer application. Addition of Ca2Fe2O5 in PZN-PZ-PT
suggests no essential improvement of electrical properties and
resulted in profounfly lowering Tc point then the species with
adding MnO2 orSnO2 did, which turnd out to be inexpdeient to
current transducer design, theaddition of Ca2Fe2O5 in PZN-PZ-PT
should be deliberately controlled.
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