Pb(Mg1/3Nb2/3)O-3-PbTiO3 (PMN-PT) ceramics with base compositions close to
the morphotropic phase boundary are potential materials for many applicatio
ns such as transducers and actuators due to their high dielectric constants
and electromechanical coupling factors. However, their dielectrical and me
chanical losses are too high for high-power applications. In this pager, th
e dielectric and electromechanical properties of piezoelectric PMN-PT ceram
ics were investigated in specimens containing various A-site and B-site sub
stituents with the goal of developing lower loss materials for wider applic
ations. Emphasis was placed on various transition metal cation substituents
of both lower and higher valences. Mn substituent was found to be the most
promising substituent investigated for developing high power low loss piez
oelectric PMN-PT ceramics.