Magnetic property calculations for B2-Co/sub x/Al/sub 1-x/ structures at the interface of Co-Al multilayer

The magnetic property of B2-Co/sub x/Al/sub 1-x/ as a function of Co atomic concentration was investigated using the ab initio method. The antistructured (AS) supercell model based on B2 structure was employed to calculate the magnetic moment of the Co/sub x/Al/sub 1-x/ compounds originated from spontaneous intermixing of Co atoms with Al surface atoms. In the case of Al-rich Co/sub x/Al/sub 1-x/, no apparent ferromagnetism was represented. However, the magnetic moment was calculated to be rapidly increased with Co concentration in the range above 50 atomic % and was saturated at a level of a pure HCP Co system. Ferromagnetism in Co/sub x/Al/sub 1-x/ alloys can be attributed to the existence of local BCC-Co and local AS-Co atoms.