The matrix and inclusions of 0-3 composites of lead titanate (PT) in polyvi
nylidenefluoride trifluoroethylene (P(VDF-TrFE)) have been independently po
led by a special poling method. The polarization states of both constituent
s are investigated by the measurement of the dynamic pyroelectric coefficie
nts of the composites in the temperature range of 20-90 degrees C, within w
hich the copolymer matrix undergoes a ferroelectric-paraelectric phase chan
ge. The pyroelectric coefficients of PT and P(VDF-TrFE) have the same sign,
while their piezoelectric coefficients have opposite signs. This allows th
e preparation of composites with enhanced pyroelectric but reduced piezoele
ctric activity when the matrix and inclusions are polarized in the same dir
ection, or vice versa if the constituents are oppositely polarized. For a P
T volume fraction of 27% it was possible to prepare a pyroelectric composit
e with vanishing piezoelectric activity or a piezoelectric composite with v
anishing pyroelectric activity by poling the matrix and inclusions in paral
lel or antiparallel directions. (C) 2000 American Institute of Physics. [S0
003-6951(00)04719-7].