Study of NiZn ferrite absorption: Effect of relative density and microstructure

A study to optimize the reflectivity of ferrite absorbers is presented. The study considers the variation of the magnetic loss factor with the evolution of fired relative density and microstructure of ferrites made from a Zn-Ni-Cu ferrite powder, and from mixture of Zn-Ni and a Cu ferrite powder. From the results, an equation which relates the magnetic loss factor to fired relative density, average grain size, and grain size distribution width, is proposed. This equation is valid for the ferrites studied, which had an average grain size below 10 mum and a grain size distribution width below 30 mum.