Structural and magnetic study of MBE-UHV evaporated (Fe/Y) multilayers

Abstract UHV evaporated (Fe/Y) n multilayers deposited into a MBE evaporator on MgO substrate were investigated by RHEED, GXRD, high-angle XRD, 57 Fe Mossbauer spectrometry at room temperature, and magnetization measurements at 300 and 5 K. The RHEED study was performed for (Fe 15 nm/Y) bilayers as a function of the Y thickness and for two (Fe/Y) n= 5 multilayers ( t Fe = t Y =0.5 nm and 1.0 nm) to determine the growth and the nature of the interfaces. The GXRD, high-angle XRD, 57 Fe Mossbauer spectrometry at room temperature, and magnetization measurements studies were performed as a function of the Fe layer thickness ( t Fe =0.5–6.0 nm) on (Fe t Fe /Y 1.0 nm) n> 5 multilayers deposited at 300 K. The Mossbauer paramagnetic doublet obtained at 300 K for t Fe =0.5 nm, is characteristic of the Fe–Y interfaces. The crystallization of BCC Fe in the center of the Fe layers occurs for t Fe between 0.5 and 1.0 nm indicating that the Fe–Y interfaces are very sharp compared to other deposited (Fe/Y) multilayers. For (BCC Fe/Y) multilayers, the Mossbauer and the magnetization results indicate that the Fe–Y interfaces thickness remains constant as t Fe increases. In average, only one monolayer of Fe is involved at each Fe–Y interface.