Influence of oxygen and nitrogen on impedance and magnetoimpedance of soft magnetic CoFeZr nanoparticles embedded in alumina matrix

It was revealed that the magnetic state and impedance of the (Co
₄₅
Fe
₄₅
Zr
₁₀
)
_x
(Al
₂
O
₃
)
_100-x
films strongly depend on a gas atmosphere of sputtering. At the deposition of the films in the presence of oxygen or nitrogen gases, the region of the superparamagnetic state was expanded far beyond the percolation threshold x
_C
determined for the films deposited in pure Ar gas. An inductive contribution in equivalent circuits of the studied nanocomposites is evidence that the current-conducting routes within the film bulk look like a system of nanocoils embedded in alumina matrix.