Study of physical properties of nanocrstalline nickel

–The dielectric property of Nanocrystalline nickel is studied. Ni nanocrystal have been synthesized by the thermal decomposition of the Ni (acac)2 [Nickel (acetylacetonate)2], oleylamine complex as a precursor . Trioctylphosphine [CH3(CH2)7]3P was used as both solvent and surfactant for control the size of the nanoparticles. Characterization of the nanoparticles has been done by the XRD and TEM method, XRD suggests that particle size is about 1nm while it is about 1-10nm from TEM data. The dielectric properties of this sample are studied in a wide range of temperature (17K-300K and frequency (1Hz-1MHz). The dielectric constant decreases with increasing frequency which is described by polarization. The electrical conductivity increases with increasing frequency which is explained by considering the hopping mechanism. This is in addition to the size effect expected in these metal nanoparticles, which shall lead to semiconducting behavior. The AC-conductivity slowly increases with increasing temperature. The significant change in the dielectric constant for this Nanocrystalline nickel is observed as temperature is varied showing that conduction processes are thermally activated. Keywords––Dielectric property; Nanocrystalline nickel; Electrical conductivity; Frequency