Abstract: The effect of annealing temperature on the particle size and on the magnetic properties of cobalt oxide Co₃O₄ nanoparticle has been investigated. Single phase Co₃O₄ nanoparticles were synthesized by co-precipitation route and their structure was confirmed through X-ray diffraction analysis. The average crystallite sizes of the nanoparticles as determined from the X-ray diffraction were found to lie in the range of 22 to 29 nm. At room temperature, these particles show ferromagnetic response at 450⁰C and  with increasing annealing temperature, the particle size increases and the tendency of cobalt Co₃O₄ nanoparticles shifts towards slightly superparamagnetic behaviour. The coercivity decreases with increasing particle size, as the annealing temperature increases.
 
Key words: Cobalt Oxide nanoparticle, crystallite size, saturation magnetization, coercivity, ferromagnetism

Cite: Prianka Sharma and Anshu Sharma, "Structural & Magnetic Properties of Cobalt Oxide Nanoparticles at Different Annealing Temperatures," International Journal of Materials Science and Engineering, Vol. 4, No. 4, pp. 208-214, December 2016. doi: 10.17706/ijmse.2016.4.4.208-214