Yh. Chen et al., Mn-modified Pb(Mg1/3Nb2/3)O-3-PbTiO3 ceramics: Improved mechanical qualityfactors for high-power transducer applications, JPN J A P 1, 39(8), 2000, pp. 4843-4852
Piezoelectric ceramics are potential high-power electroacoustic sources, an
d have been studied for many years. However, when these devices are driven
under high-level vibration, the electromechanical characteristics depart si
gnificantly from the conventional linear piezoelectric relationships due to
the loss and nonlinear behavior in terms of elastic and dielectric propert
ies. In this paper, we present results concerning the development of modifi
ed Pb(Mg1/3Nb2/3)O-3-PbTiO3 (PMN-PT) ceramics with improved mechanical qual
ity factors for high-power application. We have focused efforts on base PMN
-PT compositions close to the morphotropic phase boundary. Evidence will be
presented which indicates that the improved mechanical quality factor resu
lts from the introduction of "hard" characteristics into PMN-PT by the subs
tituents. Investigations of the nonlinearity of the electromechanical prope
rties on the vibrational amplitude were performed using a constant displace
ment method. The degradation of the mechanical quality factor with increasi
ng drive amplitude also presents thermal stability problems for the usage o
f these materials in high-power transducer applications.