(Pb, Bi)(Ti, Fe, Mn)O3/Polymer 0-3 composites for hydrophone applications

The hydrostatic piezoelectric response of composite materials incorporating (Pb1-xBix)(Ti1-xFex)O3 ceramic fillers from the highly anisotropic tetragonal region of the solid solution system in the vicinity of the morphotropic phase boundary were measured and compared. The considerable difficulty in poling and, hence, the diminished piezoelectric response encountered as the composition of the filler is shifted closer to the phase boundary was determined to be largely due to the high conductivity of the BiFeO3-rich compositions. The ceramic was modified with Mn in an attempt to lower its conductivity. Composites incorporating the Mn-doped filler poled more rapidly and easily than the undoped material and ultimately achieved a hydrostatic figure of merit, dhgh, 40% better than that observed for the undoped samples. Among the samples investigated, the highest hydrostatic figures of merit were exhibited by samples containing the doped and undoped x = 0.5 fillers. The hydrostatic response remains stable over a broad pressure range.