Abstract
Fe-AI-Si film has a layer with inferior magnetic properties near the boundary between the film and a ferrite core. This layer, which acts as a pseudo gap in MIG heads, is caused by nonuniform structure of the Fe-AI-Si film and the diffusion between the film and ferrite. Improvement of the properties of the Fe-Al-Si film requires better crystalline orientation, smaller grain size and homogeneous film structure, which is attained by selecting optimized substrates. When the MIG head uses a single-crystalline ferrite preparing (110) plane as a gap surface, the head has no pseudo output as does a MIG head of poly-crystalline ferrite with Fe-Ni/Fe-Al-Si double layer film, because both MIG heads have good crystalline orientation and homogeneous film structure.
