Soft Magnetic Properties of FeSiN/Ceramics Multi-Layers

Magnetic and structural properties of multilayer FeSiN/ceramic films produced by dual-type sputtering were investigated. Laminating of FeSiN with ceramic layers enhanced not only the frequency response of the permeability ¿, but also the value of ¿. These soft magnetic properties of as-deposited films were found to be strongly related to the substrate temperature Tsub, but were independent of the kind of ceramic used. Multilayered FeSiN/AIN films deposited at Tsub=300°C exhibited a large ¿ (at 5 MHz) of about 5,000 and a saturation induction Bs of more than 17 kG. SEM observation suggested that the soft magnetic properties of FeSiN-base multilayers arise from the decrease in magnetic anisotropy of the assembly of magnetically interacting small grains, and also from the (111) plane orientation of the grains. Most multilayered films exhibited greater thermal resistance to aging up to 600°C, because the ceramic layers prevent the growth of ¿-Fe grains.