Influence of multilayer modulation on structural and magnetic features in the Pt/Sm-Co system

In this work, we study the influence of Pt under layer in Pt/Sm-Co/Pt trilayers and in Pt/Sm-Co multilayers. In both cases, Pt under layer seems to impose better crystallinity to Sm-Co layer and certainly promotes the evolution of the hard-magnetic SmCo(5) phase. Particularly, in the case of multilayer form, where multiple interlayers of Pt each one serving as a dedicated underlayer for the deposition of a specific Sm-Co layer, enhanced crystallinity is observed. Moreover, post-deposition annealing facilitates these features at relatively lower temperatures (similar to 400 degrees C) than those met in thin film cases. This behavior is also followed by enhancement of saturation magnetization, while higher temperature post-deposition thermal treatment seems to deteriorate structural and magnetic features. If annealing temperature gets over 550 degrees C macroscopic magnetic features depress, probably due to domination of annealing-activated processes such as Sm oxidation and formation of non-magnetic phases since Pt diffuses throughout the whole magnetic layer. (C) 2009 Elsevier B.V. All rights reserved.