Cr underlayer lattice modulation through alloying and multi-layer construction

The lattice parameter (a) of bcc CrX films can be predicted using the weighted average of the Cr and X atomic radius. However, a of the sputtered CrX film depends strongly on substrate biasing. a of the underlayer can also be modified using a CrX/Cr dual layer construction with different CrX alloys. By adjusting the thickness fraction of the CrX layer within the CrX/Cr underlayer structure, various a within the upper and lower fraction limits can be realized. Hence, a can be fine tuned to lattice match the Co-alloy and enhances the Mrt of the magnetic film.