K. Sumi et al., Structure and piezoelectric properties of 0.9 Pb(Zr,Ti)O-3-0.1 Pb(Mg,Nb)O-3 films prepared by metalorganic deposition process, JPN J A P 1, 38(2A), 1999, pp. 886-889
The 800-nm-thick 0.9 Pb(Zr,Ti)O-3-0.1 Pb(Mg,Nb)O-3 (PZT-PMN) were prepared
by metalorganic deposition (MOD) process on Ti/Pt/Ti bottom electrodes. The
structure of the films was investigated by scanning electron microscopy an
d X-ray diffraction. The piezoelectric properties of the films were charact
erized by measuring the electrically induced strain using the cantilever me
thod to determine the piezoelectric charge constant (d(31)) and by measurin
g the mechanically induced voltage. The films retain the tetragonal perovsk
ite structure with both [100] and [111] preferred orientations anti are mad
e up of columnar grains whose size ranges from 100 nm to 200 nm. The plot o
f strain versus electrical field shows a hysteresis loop, which reveals tha
t the strain depends on the polarity Of the top electrode. The unpoled film
is virginally polarized toward the bottom electrode. As a result, d(31) at
an electrical field of 170 kV/cm is 190 pC/N for positive polarity and 166
pC/N for negative polarity.