PIEZOELECTRIC AND OPTICAL PROPERTIES OF SrDOPED PZTNM CERAMICS

1
PIEZOELECTRIC AND OPTICAL PROPERTIES OF Sr-DOPED
PZT-NM CERAMICS Elena Dimitriu, Rodica Ramer, C.
Ghica, A. Iuga, V. Ghiordanescu National
Institute for Material Physics, RO76900,Magurele,
P.O.Box MG-7, Romania School of Electrical
Engineering, University of South Wales, Sydney
2052, Australia
ABSTRACT PZT ceramic samples doped with
strontium, niobium and magnesium were sintered in
the temperature range of 1180oC-1230oC.
Tetragonal phases were identified by XRD method,
and lattice parameters of the material were
calculated. Typical TEM micrographs were
obtained. Optical reflection spectra in visible
region were measured. Very dense samples, with
Curie temperature over 200oC, were obtained.
Piezoelectric properties were determined by means
of resonance antiresonance method. The
variation of relative dielectric constant with
the temperature was studied. The material could
be used for low power resonant and non-resonant
devices.  Keywords PZT, microstructure, optical
spectra, dielectric constant
X-ray diffraction pattern of PZT-type material
substituted with Sr, Mg and Nb
The variation of the relative dielectric constant
and density with the sintering temperature
TEM image of a sample sintered at 1220oC
SAED pattern of a sample sintered at 1220oC
Optical reflectance spectra of the samples
sintered at 1205oC and 1230oC
Electromechanical coupling factors vs. temperature
5 Temperature dependence of the relative
dielectric constant of the material sintered at
1) 1205 oC 2) 1220oC 3)1230 oC 4)1180 oC
The Ti2ions transitions in the crystal field
approximation are 3T1g(P)? 3T1g , and
3A2g?3T1g a large absorption band is observed at
about 650nm. For the Ti3 ion, the transitions in
the tetragonal field are 2B1g?2B2g and
2A1g?2B2g a large absorption band is observed at
about 550nm.
PZT-type materials with Sr, Mg, Nb as substitutes
in A- and B position have been prepared by
ceramic technique. Tetragonal phases were
identified by XRD method, and lattice parameters
of the material are a b 0.401 nm and c
0.408nm. Optical reflection spectra in visible
region reveal transition of titanium from 4 to
2. The relative dielectric constant increases
linearly up to a value of over 5700 with the
sintering temperature and with the frequency.
Acknowledgments. The authors acknowledge the
financial support of the European POLECER network
and University of South Wales, School of
Electrical Engineering, Sydney, Australia