Abstract:
Here in this work we have followed a chemical way of synthesis (Coprecipitation) to synthesize BaFe12O19 nanoparticles to study the variations occurred in its Electric and Dielectric properties in the presence of MWCNTs. These nanoparticles are decorated on the outer surface of MWCNTs with the help of Ultrasonication by using O-xylene as dispersing medium. By the help of ultrasonication 5 samples were prepared containing 0,1,2,3 and 5% MWCNTs. XRD patterns revealed the formation of pure Hexaferrites phases of pure and decorated nanoparticles. The average crystallite size found for pure BaFe12O19 nanoparticles was 35nm. SEM shows the hexagonal, uniformly distributed homogenous nanoparticles grown by co-precipitation method. It also shows the successful attachment of nanoparticles on the outer surfaces of MWCNTs. FTIR results shows the absorption peaks for BaFe12O19 nanoparticles at 434.47,598.43 and 1431.80 cm-1. A shift occurred in the absorption peaks of prepared composites (BaFe12O19/MWCNTs), which shows the successful attachment of BaFe12O19 on the outer surfaces of MWCNTs. The dielectric parameters were studied in the frequency range of 1 MHz – 5 GHz. Dielectric constant (ε’), Dielectric loss (ε”), Dielectric loss tangent (tan δ) decreases with increase in frequency and increases with increase in wt% of MWCNTs in BaFe12O19/MWCNTs nanocomposites. The A.C conductivity is maximum at higher frequency which represent the dominance of hoping conductivity over band conductivity. The electric modulus increases with increase in frequency and decreases with increase in wt% of MWCNTs in BaFe12O19/MWCNTs nanocomposite. The ColeCole plot of electric modulus gives semi circles and relaxation time at higher frequencies. The impedance (Z) decreases with increase in frequency and also decreases with increase in wt% of MWCNTs in BaFe12O19/MWCNTs nanocomposite. The resistivity “lnρ” of the prepared samples was plotted against “1/kBT” in the range 20 – 32 (ev)-1. It represents decrease of resistivity with increase in temperature. The drift mobility(μd) shows maximum values at higher temperature and it increases with increase in wt% of MWCNTs in BaFe12O19/MWCNTs nanocomposite. These variations in the Electric and Dielectric properties of BaFe12O19 due to MWCNTs made it an important material for the electromagnetic devices.
