To obtain an optimum coupling of the pyroelectric activity of ferroelectric inclusions to the electrodes of a 0–3 composite film, the dielectric constants of matrix material and inclusions would have to be comparable. While there is no way to substantially raise the real part of the dielectric constant of the polymer matrix, the imaginary part can be increased by an appropriate doping. The results from theoretical modelling predict a significant increase of the pyroelectric coefficient and especially the pyroelectric signal power. Experimental investigations on composites of lead titanate particles in polyurethane doped with potassium bromide show the improvement and give hints to further optimization of its pyroelectric performance.
Acknowledgments
Paper originally presented at IMF-11, Iguassu Falls, Brazil, September 5–9, 2005; received for publication January 26, 2006.