PLZT-P(VDF/TFE) 0-3 composites with nanosized lead lanthanum zirconate titanate (Pb 0.92 La 0.08 )(Zr 0.65 Ti 0.35 )O 3 (PLZT 8/65/35) ceramic powders of volume fraction Φ up to 0.2 were fabricated using PLZT powders imbedded in a copolymer P(VDF/TFE)(0.98/0.02) matrix. The PLZT nanopowders were prepared by the sol-gel technique. The PLZT-P (VDF/TFE) composite samples were prepared from ceramic and polymer powders by the hot-pressing method. Dielectric response was studied in the frequency range from 100 Hz to 1 MHz and at temperatures from 100 to 450 K. The pyroelectric properties were studied by dynamic method with modulation frequency from 1 to 100 Hz. The dielectric response of the ceramics-polymer composite was found to be a combination of the responses of the pure polymer and the ceramics: (1) the addition of the PLZT ceramics increases the value of the dielectric permittivity ɛ′, (2) the composite shows the maximum of the permittivity coming from the PLZT ceramics, (3) the temperature dependences of the dielectric loss tgδ are characterized by the maximum attributed to the α-relaxation (glass transition) in the pure polymer. The pyroelectric coefficient of the composite increases from ∼20 μC/m 2 K in pure P(VDF/TFE) to ∼140 μC/m 2 K in the composites of Φ=0.15.
Dielectric response of poly(vinyl chloride), (PVC), loaded with different amount of Ba 0.3 Na 0.7 Ti 0.3 Nb 0.7 O 3 (BNTN) ceramic powders was investigated in frequency range 100 Hz-1 MHz and temperature range 100-450 K. Ceramic solid solution of barium titanate and sodium niobate with composition Ba 0.3 Na 0.7 Ti 0.3 Nb 0.7 O 3 was obtained from BaCO 3 , TiO 2 , Na 2 CO 3 and Nb 2 O 5 by conventional method. Powders were prepared by grinding of ceramics. The obtained ceramics, used to produce BNTN-PVC composites, are characterized by the relaxor behaviour with a broad peak of dielectric permittivity " 0 at T m % 230 K. The microstructure of the powders was observed and the grain size was estimated using scanning electron microscope Hitachi S-4700. The EDS analysis confirms the qualitative and quantitative chemical composition of powders and ceramics. The BNTN-PVC composite samples of 0-3 connectivity were prepared from ceramic and polymer powders by hot-pressing method. The dielectric response of the composites displays features originated from the PVC polymer modified by those of BNTN ceramics. The relaxation time of the -process of PVC obeys the Vogel-Fulcher law and decreases with increasing volume fraction of the ceramics.
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