Effect of chromium substitution on structural, magnetic and electrical properties of magneto-ceramic cobalt ferrite nano-particles

Single phase cobalt ferrite and chromium-substituted cobalt ferrite magneto-ceramic nano-powders are prepared by sol-gel self-combustion method. Chromium substitution is made within in the range of 10 mol% of iron in the cobalt ferrite powder. The XRD analysis of the prepared samples confirms the formation of single-phase nano-particles. Chromium substitution effect on the magnetic and electrical properties of cobalt ferrite nano-powders (in pellet form with high porosity) have been discussed. The effects are attributed to the mismatch between the magnetic moments of chromium and iron ions. In this paper we show that self-combustion method, without having to change the pH of precursor, is a simple and viable technique to synthesize cobalt ferrite nano-powders. Chromium substitution helps to tune the magnetic properties of cobalt ferrite. From AC dielectric permittivity analysis we observe that chromium substitution suppresses the small electrical relaxation peak at 1 MHz frequency of cobalt ferrite. This behavior can find application in magnetic storage devices.