Cadmium cobalt ferrite nanoparticles with a chemical formula of CdxCo1-xFe2O4 (x = 0.0, 0.1, 0.2, 0.3, 0.4, 0.5 & 0.6) (CCF) were prepared via the citrate-gel auto combustion method followed by annealing at 773 Kelvin for 4 hrs in air. Further, the samples were characterized for structural, morphological, elemental, functional group, electrical and thermoelectric properties analysis. The X-ray diffraction patterns showed the single phase cubic structure. The crystalline size of the synthesized Co-Cd ferrites nanoparticle is found in the range of 11 to17 nm. In addition, with an increase of Cd content, we noticed that lattice constants (a) and x-ray density (dx) values were increasing from 0.8419 – 0.8496 nm and 5.222 – 5.777 g/c.c., respectively. Morphological properties were examined by scanning electron microscopy (SEM) & Transmission electron microscopy (TEM). The tetrahedral (υ1) and octahedral (υ2) frequencies were observed at around 400 - 600 cm-1. The electric and dielectric properties such as DC-electrical conductivity (σdc), dielectric constant (ε'), dielectric loss (ε") and thermoelectric power parameters were calculated. At a low temperature of 300 K, the samples express the p-type semiconducting nature due to having +ve value of ‘S’ while the same shows –ve value at high temperature suggesting the n-type semiconducting behavior. Moreover, the magnetic Curie-transition temperatures were determined as a function of composition and noted to be decreasing from 753 – 653 K respectively.
Atomic resolution electron microscopy of cobalt ferrite nanoparticles
