High coercivity in heterogeneous Co-rich CoAg very thin films

The Effects of Layer Thickness on the Microstructure and Magnetic Properties of Evaporated Co/Ag Films

“…4b), which implies that metastable fcc Co grows on the thick Ag layer. Similar metastable phase growths were observed in the Co/Pt [9] and Co/Cu [12] systems, in which the composition of Co was not as rich as that in the Co/Ag system [7,8]. The fact that fcc Co is found for t Co values as high as 3.0 nm also suggests extensive interlayer diffusion.…”

“…For example, some metastable fcc Co phases were obtained in Co/Ag [6][7][8], Co/Pt [9], and Co/Cu [10][11][12] multilayers and granular films. Using 200 keV xenon ion mixing of nano-sized Co/Ag multilayers about 40 nm thick, metastable and fcc phases were formed at room temperature [6].…”

“…In Co/Ag multilayers and granular films produced by electrodeposition [7], the Co/Ag films with a Co concentration up to 85% showed an fcc structure of Ag only and above 85% Co showed an fcc structure of Co only. In very thin Co/Ag films [8] prepared by dc magnetron sputtering from 5 to 50 nm with Co volume fractions ranging from 65 to 100%, selected area electron diffraction (SAD) patterns of as-deposited films consisted of broad and diffuse rings that can be indexed as an fcc phase with a lattice parameter close to that of Ag. Extra rings that can be indexed as fcc Co appeared in a 10 nm annealed Co/Ag 65 : 35 vol.% film.…”