  The temperature dependence of elastic, dielectric, and piezoelectric
properties of (65-x)Pb(Mg1/3Nb2/3)O3-xBaTiO335-PbTiO3 ceramics with x=0, 1, 2,
3, and 4 was investigated. Compound with x=2 was found to exhibit a large
piezoelectric response (d31=-170 pC/N, d33=530 pC/N at 300 K). Particularly,
its d31 value was nearly a constant over a temperature range from 185 to 360 K.
A broad ferroelectric phase transition tuned by BaTiO3 doping was deduced from
the dielectric constant, elastic compliance constant and Raman spectra. The
temperature-stable piezoelectric response was attributed to the counter-balance
of contributions from the dielectric and elastic responses.
