| Research Abstract |
Artificially superstructured as well as compositonally modulated multilayers show often enhanced magnetic anisotropy with the easy axis perpendicular to the film plane, and this anisotropy is very attractive in applications such as magnetic and magneto-optic recording. In this research, we have investigated magnetic properties in two type of multilayers, one is noble metal (Nm) /transition metal (TM) multilayer, the other is rareearth (RE) /transition metal containing light RE, which have advantage to magnetooptic Kerr effect at short wavelength compared with usial TbFeCo alloy.
I. NM/TM multilayers
Multilayers consists of NM (Pd, Pt, Cu, Au, PdSi) and TM (Co, Ni, PdCo, PtCo, CoZr) layers were prepared by rf sputtering method on glass and/or MgO single crystal substrates. The perpendicular magnetic anisotropy was examined in relation to the magnetostriction, lattice misfits, crystanity and crystal orientations. The results suggest that the perpendicular magnetic anisotropy in NM/PdCo-alloy multilayers originates from the magnetoelastic energy of the PdCo layers under a stress due to the lattice misfits. In both Pd/Co and Pd/Ni multilayers, the anisotropy, was found to depend on the crystal orientation, and the dependence could be attributed to the anisotropic magnetostriction constants of these alloys.
II. RE/TM multilayers
Magnetic and magneto-optic properties have been investigated for NdGd/Fe and NdGd/FeCo multilayers prepared by rf sputtering method. At bilayer period of 10 to 15 A, perpendicular magnetic anisotropy showed the maximum value of about 2.5 X 10^6 erg/cm^3, magneto-optic Kerr rotation in the multilayers reach 0.33 at 400 nm, reflecting the contribution of Nd.
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