Spacer-layer–induced spin reorientation in Ni/Cu/Ni sandwiches

Cavendish Laboratory - Cambridge, CB3 0HE, UK

Received: 3 January 1996
Accepted: 28 June 1996

Abstract

We report polar magneto-optical Kerr effect studies of Cu spacer layer on the perpendicular magnetic anisotropy in 70 Å  Ni/Cu wedged/70 Å  Ni structures. With increasing Cu thickness, the magnetic easy axis of the top Ni layer continuously changes to the direction perpendicular to the surface. This results from the gradual strain relaxation of the Cu spacer with increasing thickness followed by increasing strain in the top Ni layer. A crossover from coherent to incoherent strain in Cu spacer around 18 Å  results in a dramatic non-monotonic dependence of magnetic anisotropy on the Cu thickness.