To obtain a core which maintains high durability in a manufacturing equipment, at a low cost, and which has an excellent electric characteristic, by using a sintered body of α-ferric oxide as an inductance device core.
The inductance device core is a sintered body of α-ferric oxide (α-Fe2O3) including one or more of Mg, Ca, Sr, Ba, Al, Si, P, Mn, Co, Ni, Cu, Zn and the like, in the form of oxides, as impurities. The content of iron in the core material is set, when reduced to Fe2O3, within a range of 75-99.9wt%. As the transverse strength of the core, its transverse strength by three-point bending is 6kgf/mm2 or higher, its specific resistance is l06Ω/cm or higher, and, its Vickers hardness is within a range of 800-1500. The core is manufactured by: combining the ferric oxide as the material with additive and binder; forming the mixture into particles and drying the particles; forming the particles into a predetermined core shape; and sintering the core at a temperature of 9501500°C for 5 minutes to 5 hours in an air atmosphere.
ITO KO
KAKINUMA OSAMU
