Research of Ultra High Density Magneto-optical Recording Material

从<111><100>感生各向异性出发，估算了[111]取向的多晶PdCo和PtCo合金薄膜以及多层膜的磁致伸缩常数λ_和λ_。结果表明，Pd/Co和Pt/Co多层膜的磁致伸缩常数并不取决于面心立方结构Co的磁致伸缩常数，而是受PdCo和PtCo合金磁致伸缩常数的强烈影响。这一结果暗示了界面处电子杂化和/或合金形成的效应。测量了Cr2 O3 Co薄膜的磁光克尔磁滞回线及其能谱。在Au/20 A Co/Au三明治结构中，Kerr旋转和Kerr椭圆率的谱线形状与体数据计算结果一致。随着Co厚度的减小，谱形变得与计算的谱形不同。对NdGd/Fe和NdGd/FeCo多层膜的磁性和磁光特性进行了研究。在双层周期为10 ~ 15埃时，垂直磁各向异性显示出最大值，约为2.5 × 10^6 erg/cm^3。多层膜的磁光克尔旋转在400 nm处达到0.33 nm，反映了Nd的贡献。

Magnetostriciton constants lambda_<111> and lambda_<100> were estimated for [111] oriented polycrystalline PdCo and PtCo alloy films and multilayr films (MLs) from the induced anisotropy. It was found that the mangetostriction constants of Pd/Co and Pt/Co MLs are not determined by the mangetostriction constants of fcc Co, but are strongly affected by those of PdCo and PtCo alloys. This result implies the effect of electron hybridization and/or alloy formation at the interface.Magneto-optical Kerr hysteresis loops and their energy spectra are measured for ultrathin Co films. In Au/20 A Co/Au sandwiches, the spectra shape of the Kerr rotation as well as the Kerr ellipticity agrees with those calculated from bulk data. With decreasing Co thickness, the spectral shape becomes different from the calculated one. The imaginary prot of off-diagonal conductivity was also estimated for ultrathin Co films.Magnetic and magnetooptic properties have been investigated for NdGd/Fe and NdGd/FeCo multilayrs prepared by rf sputtering method. At a bilayr period of 10 to 15 A, perpendicular magnetic anisotropy showed the maximum value of about 2.5 X 10^6 erg/cm^3. Magnetooptic Kerr rotation of the multilayrs reach 0.33ﾟ at 400 nm, reflecting the contribution of Nd.