Piezoelectric polymer-ceramic composites are promising materials for transducer applications, and they are widely used in underwater hydrophones, biomedical imaging with ultrasound, and nondestructive testing applications. The critical factor in the 0-3 composite is to ensure homogeneous distribution of the filler in the matrix. To ensure this objective, PVDF-PZT composite was prepared by two different routes: hot press and tape casting techniques. Loss on ignition and scanning electron microscopy studies were conducted to find out the uniformity of the composites prepared. It is found that hot press technique gives better uniformity compared to tape casting technique. PZT concentration was varied from 20 to 60 vol %. Physical and dielectric properties were studied. FT-IR, DSC, and XRD characterization studies of PVDF were also recorded. Density of the composites was 2.74 to 5.13 g/cm 3 as PZT concentration increased from 20 to 60 volume fractions. The dielectric constant of composites at 1 MHz varied from 16.74 to 98.48 as PZT concentration increased from 20 to 60 volume fractions. Hot press technique that combines solution and melt processing was found to be the better method for the preparation of 0-3 composites.

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a b s t r a c tThe laser-induced luminescence studies of the rare earth titanates (R 2 Ti 2 O 7 ) (R = La, Nd and Gd) using 355 nm radiation from an Nd:YAG laser are presented. These samples with submicron or nanometer size are prepared by the self-propagating high temperature synthesis (SHS) method and there is no known fluorescence shown by these rare earths in the visible region. Hence, the luminescence transitions shown by the La 2 Ti 2 O 7 near 610 nm and Gd 2 Ti 2 O 7 near 767 nm are quite interesting. Though La 3+ ions with no 4f electrons have no electronic energy levels that can induce excitation and luminescence processes in the visible region, the presence of the Ti 3+ ions leads to luminescence in this region.

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