Paper Title
Influence of Starting Powder Milling on the Permeability and Core Loss Density of Mn-Zn Ferrite in the High Frequency Range

Abstract
The industrial Mn-Zn powder was additionally milled for 1 hour and sieved through a 325 and 400 mesh. These powders are used to fabricate toroidal shaped samples which are sintered at 1200�C. Permeability and core loss density were measured on the fabricated toroidal cores using modified Watt-meter method. The influence of additional millingof the starting industrial Mn-Zn powder on the grain size and subsequently on the magnetic properties of ferrite was evaluated.The sample fabricated from powder sieved through a 325 mesh exhibits enhanced high-frequency relative permeability (μ� of 200 and μ� of 90) and lower core loss density (400 kW/m3 at 5 MHz and 4 mT) compared to sample sieved through a 400 mesh. These show the significance of the milling and sieving medium and their parameters. Keywords� Permeability, Core Loss Density, Mn-Zn Ferrite