Publications

Electrodeposition of high magnetostrictive cobalt-iron alloy films for smart tags and sensor applications

Pillars, Jamin R.

Magnetostrictive CoFe films were investigated for use as magnetoelastic tags or sensors. The ability to electrodeposit these films enables batch fabrication processes to pattern a variety of geometries while controlling the film stoichiometry and crystallography. In current research looking at CoFe, improved magnetostriction was achieved using a co-sputtering, annealing, and quenching method1. Other current research has reported electrodeposited CoFe films using a sulfate based chemistry resulting in film compositions that are Fe rich in the range of Co_0.3-0.4Fe_0.7-0.6 and have problems of codeposition of undesirables that can have a negative impact on magnetic properties. The research presented here focused on maximizing magnetostriction at the optimal stoichiometry range of Co_0.7-0.75Fe_0.3-0.25, targeting the (fcc+bcc)/bcc phase boundary, and using a novel chemistry and plating parameters to deposit films without being limited to “line of sight” deposition.