Abstract:
A series of Cerium substituted Cobalt Nickel Ferrite nano particles with nominal
composition Co0.5Ni0.5CexFe2-xO4 (where x=0.00, 0.05, 0.10, 0.15, 0.20) have been synthesized by chemical co-precipitation and sol–gel auto combustion techniques. Samples
were characterized by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM),
Fourier Transform Infrared Spectroscopy (FT-IR), dielectric properties and DC electrical
resistivity. XRD confirmed the cubic spinel structure for both syntheses routs. The unit
cell parameter increased by increasing Ce concentration from 8.359 Å to 8.372 Å for coprecipitation and from 8.353 Å to 8.367 Å for sol-gel while crystallite size decreased
from 24 nm ±1 nm to 16 nm ±1 nm for co-precipitation and from 27 nm ±1 nm to 18 nm
±1 nm for sol-gel. Theoretical density increased from 5.335 g/cm3
to 5.692 g/cm3
for coprecipitation and from 5.347 g/cm3
to 5.366 g/cm3
for sol-gel. SEM results show presence
of uniformly distributed and almost spherical in shape particles for both techniques. FTIR
measurements confirm vibrations at tetrahedral and octahedral sites by two fundamental
absorption bands υ1 around 600 cm-1
and υ2 around 400 cm-1
. DC electrical resistivity of
x=0.00 sample is higher than Ce substituted ferrite samples and in the range of 108 Ω-cm
at 373 K. Dielectric properties are studied from 100 Hz to 5 MHz as a function of frequnecy
