Electrodeposited amorphous Co-P based alloy with improved thermal stability

As result of its high resistivity and good magnetic properties, electrodeposited amorphous Co-P (a-Co-P) is an attractive material for use in the integration of on-chip inductors into silicon process technology. However as an amorphous material, the properties of a-Co-P are dramatically changed upon crystallization. This paper reports a novel electrodeposited magnetic alloy, a-Co-P-Re that shows a significantly improved thermal performance in comparison to a-Co-P, retaining coercivity, Hc<92 A/m after a thermal anneal at 298 deg. C. These results were obtained for alloys with a composition of; Co 100-x-y, Px, Rey where; 9.7 at%<x<17.5 at% and 0.4 at%<y<7.6 at%. Other important properties namely, saturation magnetisation, Ms, and resistivity, ρ, appear to be largely unaffected by the addition of Re.