Magnetic Properties of Artificial Super Lattice and its Application for magneto-optical Recording Media

人工超结构和复合调制多层膜通常表现出增强的磁各向异性，其易轴垂直于薄膜平面，这种各向异性在磁和磁光记录等应用中非常有吸引力。本文研究了贵金属(Nm)/过渡金属(Tm)多层膜和稀土/轻稀土(RE)/过渡金属(Tm)多层膜的磁性能，与常用的TbFeCo合金(Nm/Tm)多层膜相比，稀土(RE)/轻稀土(TbFeCo/Tm)多层膜具有更好的短波磁光克尔效应。研究了垂直磁各向异性与磁致伸缩、晶格失配、结晶度和晶体取向的关系。结果表明，Nm/PdCo合金多层膜的垂直磁各向异性来源于晶格失配引起的应力作用下PdCo层的磁弹性能。在Pd/Co和Pd/Ni多层膜中，各向异性与晶体取向有关，这种各向异性与合金的各向异性磁致伸缩常数有关。II.研究了用射频溅射方法制备的NdGd/Fe和NdGd/FeCo多层膜的磁性和磁光性质。在10~15A的双层周期内，垂直磁各向异性的最大值约为2.5×10~(-6)erg/cm~(-3)，在400 nm处的磁光克尔转角达到0.33，反映了Nd的贡献。

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 multilayersMultilayers 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 multilayersMagnetic 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.