FERRITE MAGNETIC SUBSTANCE

摘要

PURPOSE:To realize a high permeability and a low magnetic loss even in a high-frequency region (MHz band) by a method wherein a magnetic powder subjected to surface treatment with an organic material containing a metal component is molded and heat-treated. CONSTITUTION:A mixture which is composed of 53mol% of Fe2O3, 25mol% of MnO and 22mol% of ZnO is baked at 1320 deg.C for 6 hours to obtain an Mn-Zn ferrite magnetic powder. The powder is crushed to obtain a magnetic powder of 1mum or lower. The powder is immersed in a solution in which ethanol, pure water and HCl have been added to tetraethoxysilane; surface treatment is executed; a binder is added to and mixed with the magnetic powder. The mixture is granulated; after that, it is compressed and molded to be a toroidal shape. The molded body is heat-treated in nitrogen or in air at 1200 deg.C for one hour to form a ferrite magnetic substance. The ferrite magnetic substance which is obtained by molding and heat-treating the magnetic powder subjected to surface treatment with an organic material containing a metal component can cover a high-resistance oxide surely and uniformly at a ferrite grain boundary. Thereby, a high permeability and a low magnetic loss can be realized even at a high-frequency region.