Kouichi Kugimiya

Magnetic thin films with anisotropic grain-growth in the 1 or 3-dimensional direction

Publisher Summary This chapter investigates nanocrystalline magnetic materials, made of small grains under 20nm, to realize soft magnetic materials with high saturation magnetic flux density, Bs. It investigates the magnetic, structural, and corrosive properties of sputtered fesialtion. Though the general nanocrystalline materials are obtained from the amorphous state with isotropic grain growth by thermal treatment, the developed materials have fine crystalline textures as prepared state. According to the TEM observations, the microstructures of the film annealed at 500°C consist of needle shape fine grains in 1-dimensional growth and/or dendritic in 3-dimensional growth. The typical grain is over 200nm in height and 20nm in width. The developed materials exhibit high corrosion resistance with high Bs as well as good soft magnetic properties caused by their compositions and structures. The developed materials have Bs of 1.3T, permeability of 3000–8000, respectively, and have higher corrosion resistance than FeSiAl with Bs of 1T.