Soft Magnetic Properties of Fe-Si-N Thin Films

The crystal structure and magnetic properties of sputter-deposited Fe-Si-N films were investigated. Fe-Si-N films had a single α-Fe phase, and with higher N content, two phases, α-Fe and γ'-Fe
₄
N. A coercivity H
_c
lower than 1 Oe was obtained for single α-Fe phase films. The permeability μ was found to be strongly related to the substrate temperature T
_sub
during deposition. For example, deposition at T
_sub
=230°C gave rise to μ=3600 at 10 MHz. Such high values were obtained in single α-Fe phase films, which consisted of fine crystal grains with a (111) plane orientation. The permeability of films with a high Si concentration was found to have high thermal stability.