Improvement of crystallinity and exchange bias field in reverse type Ni-Fe/FeMn bilayers using Si/Ni-Fe composite type of underlayers

Composite-type Si/Ni-Fe underlayers were examined to improve crystallinity and exchange bias characteristics of the reverse-type exchange coupled layers, such as [FeMn/Ni-Fe] bilayers. A Si underlayer promoted [111] texture of fcc crystallites in the initial growth region of Ni-Fe layer deposited on it. FeMn layers deposited on the Si/Ni-Fe bilayered underlayer exhibited excellent [111] texture of fcc crystallites. The multilayer film with Si underlayer revealed a large exchange coupling field H/sub ex/ to the Ni-Fe films deposited on it after annealing in an applied field of 500 Oe. It was found that the exchange field H/sub ex/ of the film with a 50 /spl Aring/-thick Si underlayer revealed a large value of about 300 Oe. The Ni-Fe layer between Si and FeMn layers could possess a large exchange coupling field.