Investigation of Cap and Buffer Layer Effect in Co/Ni Thin Films by Ferromagnetic Resonance Technique

Abstract

In this study, the magnetic properties of Si(100)/X5/(Co0.3/Ni0.5)3/Y5 (X: Pt, Cu and Y: Pt, Cu, all thicknesses are nm) multilayers were investigated using ferromagnetic resonance technique (FMR). In sample sets all layers (buffer, cap, and Co) were grown by magnetron sputtering while Ni sub-layers were grown by molecular beam epitaxy (MBE) at high vacuum. The effective magnetic anisotropy is 300 mT when copper is used as the buffer and cap layer, 290 mT when the buffer layer is copper, and the cap layer is Pt. On the other hand, it is seen that the effective magnetic anisotropy is 350 mT when Pt is used as buffer and cap layer, and 150 mT when Pt buffer and Cu cap layer are used. Furthermore, magnetic easy axis is out of plane when the Pt buffer layer is used, while the magnetic easy axis is parallel to the plane when the Cu buffer layer is used. The results show that the buffer and cap layers of Co/Ni thin films, which are frequently used in the field of spintronics influence the magnetic properties.