PURPOSE: To obtain the amorphous core having excellent magnetic characteristics in a highly productive manner without performing a high temperature heat treatment by a method wherein a thin strip amorphous magnetic alloy is fed into a reaction chamber, film-forming source gas is supplied, and an SiO2 film is formed on the surface of the thin strip by induction heating of the thin strip.
CONSTITUTION: The thin strip 8 of amorphous magnetic alloy is fed into a reaction chamber 1, the film-forming source gas such as oxygen, SiH4 and the like and carrier gas are supplied, the source gas is decomposed on the surface of the thin strip by induction-heating the thin strip, and an SiO2 film is formed on the Surface of the thin strip 8, and the thin strip of SiO2 amorphous magnetic alloy obtained as above- mentioned is wound around the core. For example, pipes 4 and 5 with which SiH4, N2 and O2 will be introduced are coupled to one end of a quartz reaction pipe 1, the thin strip 8 of Fe-Si-B amorphous magnetic alloy is picked out from a roll 9, it is fed into the reaction chamber 1 through a suitable seal, and the thin strip 8 is rolled up by the other roll 10. A high frequency induction coil 11 is wound around a quartz pipe 1 and driven by a high frequency power source 12. An SiO2 film 4 is grown continuously on the surface of the thin strip 8 at the surface temperature of the thin strip of 300°C or thereabout using the above-mentioned device.
SHIGETA MASAO
CHO TSUTOMU
Next Patent: OXIDE MAGNETIC MATERIAL