DOMAIN-WALL PATTERNS IN MAGNETOSTATICALLY COUPLED BILAYERS

Magnetic domain-wall patterns in magnetostatically coupled bilayers se parated by a non-magnetic interlayer have been studied for different a nisotropy configurations. A numerical treatment is presented for the c ase of a parallel anisotropy axis between magnetic layers for samples with thicknesses of 1000 Angstrom for the magnetic layers and 100 Angs trom for the interlayer, For these thicknesses coupled Neel walls appe ar with a similar structure to that found in previous works on thinner films except for the much higher magnetic poles found at the interlay er boundary surfaces. Samples of Fe20Ni80/Cu/Fe20Ni80 of 500/200/500 A ngstrom thickness have been grown whilst uniaxial anisotropies were in duced in the magnetic layers with the perpendicular easy axis directio ns between them. Bitter observations show that coupling between domain walls also exists in samples with the non-parallel magnetic anisotrop y axis in both layers. (C) 1998 Elsevier Science B.V. All rights reser ved.