Improvement of the magnetic characteristics of multilayered Ni-Fe thin films by applying external in-plane field during sputtering

Abstract

Ni/sub 79/Fe/sub 21/ single layers and multilayers composed of Ni/sub 79/Fe/sub 21/ layers and paramagnetic Al interlayers were deposited using the facing targets sputtering (FTS) apparatus. During layer deposition, the external field H/sub ex/ of 200 Oe along the film plane was applied parallel or transverse to the direction of the plasma confining field H/sub p/ of about 30 Oe in the FTS apparatus. The application of H/sub ex/ parallel to the H/sub p/ direction was not significantly effective for improving soft magnetic characteristics of the films. When H/sub ex/ was applied transverse to the H/sub p/ direction, the relative permeability /spl mu//sub r/ of the Ni-Fe single layers 100 nm-thick was increased, while the coercivity H/sub c/ and the squareness ratio M/sub r//M/sub s/ of them were not varied. On the other hand, /spl mu//sub r/ of the [Ni-Fe/Al]/sub 5/ multilayers was extremely and isotropically increased while M/sub r//M/sub s/ for the multilayers was decreased down to a half value.