Dielectric Study of Polyaniline/NiFe_2O_4 Composites Prepared by Reflux Techniques

摘要

PANI/NiFe_2O_4 composites have been synthesized by in situ deposition technique by placing fine graded NiFe_2O_4 in polymerization mixture of aniline. The PANI/NiFe_2O_4 composites have been synthesized with various compositions viz., 05, 10, 15, 20 and 25 wt% of NiFe_2O_4 in PANI. The prepared composites were characterized by FTIR, XRD and SEM for structural and morphological study. The AC conductivity was studied in the frequency range 10~2-10~6 Hz. It is observed from the AC conductivity studies that the AC conductivity is found to be constant up to 10~5 Hz and there after it increases steeply which is a characteristic feature of disordered materials. The dielectric behavior was also investigated in the frequency range 10~2-10~6 Hz. It is observed from the dielectric studies the value of dielectric constant increases up to 15 wt% and later it decreases. It is seen that the tan δ values increases up to 15 wt% and then decreases thereafter. At higher frequencies these composites exhibit almost zero dielectric loss the dimensions of NiFe_2O_4 particles in the matrix have a greater influence on the conductivity values and the observed dielectric values.