Microstructural and magnetic properties of exchange-coupled Co/Fe multilayers

Cobalt/iron multilayers with different layer thickness were electron beam e vaporated in ultrahigh vacuum, keeping constant both the number of layers a nd the Co/Fe thickness ratio. Structural and magnetic properties are thorou ghly investigated with different techniques. The multilayers have clean and sharp interfaces. All samples show single-phase magnetic behavior in the t emperature range of 5-300 K, due to the strong exchange coupling between th e layers. The room temperature hysteresis loops present a sharp switching a t a field of similar to 8 kA/m, followed by a residual hysteresis extending up to saturation, at fields of several tens of kA/m. (C) 2000 American Ins titute of Physics. [S0021-8979(00)88108-6].