Study on the depth profile analysis of Fe/Co intermixing in [SmCo5/Fe]11 magnetic multilayers

Multilayer films were sputtered on Si (1 0 0) substrate by following a layer sequence of Cr (10 nm)/[Fe (4 nm)/SmCo5 (20 nm)]11/Cr (90 nm) at room temperature and subsequently, subjected to two-stage annealing. The phase composition, the extent of inter-diffusion at the SmCo5/Fe interfaces and the magnetic properties of multilayered samples were investigated by X-ray diffraction (XRD), RBS and super-conducting quantum interference device (SQUID), respectively. The XRD studies showed the crystallization of SmCo5-phase in the hard layer along with a bcc-Fe (Co)-phase in the soft layer, while the RBS depth profile analysis revealed the changes that occur in the effective Fe-layer thickness and diffused Co-content as minimal for the Fe-layer index, nFe≤5. A single-phase behavior associated with strong in-plane anisotropy was evidenced with the SQUID measurements. The observed remanence enhancement (1020 kA/m) and energy product value (286 kJ/m3) in these multilayers are discussed in the context of Fe-layer thickness and diffused Co-content.