Magneto-optical effect of MO recording media and the development of new materials

1. 稀土(RE)-过渡金属（TM）非晶合金薄膜的磁光效应(1)制备了Yb-Co非晶合金薄膜，并测量了其磁性和磁光性能。据估计，Yb原子变成2+离子而不是3+离子。结果表明，Yb原子在Yb- co合金中没有磁矩，其磁性和磁光性质与La-Co和/或Ce-Co薄膜非常相似。(2)研究了Gd- co薄膜的磁光克尔效应，其Gd含量范围为10% ~ 50%。与其他稀土不同，随着Gd含量的增加，Co的原子矩仅略有下降，这导致在较高Gd浓度下，Co的克尔旋转相对较大。通过分析克尔旋转的组分依赖性，分离了Gd和Co两个子网络磁化对克尔旋转系数的贡献，确定了400 ~ 1000 nm波长范围内克尔旋转系数的光谱。(3)利用包括本项目研究在内的所有可用数据，澄清了除RE=Eu外的RE- tm非晶合金的磁性结构。(4)对于RE- fe_ <0.8>Co_<0.2>合金薄膜，RE和TM子网络对Kerr旋转光谱的贡献是分离的，RE- fe_ <0.8>Co_<0.2>是磁光存储的重要介质。Mn化合物和/或多层新磁光材料的开发研究(1)MnBi薄膜在低温下克尔旋转显著增加，这是现有理论无法解释的。根据克尔旋转、克尔椭圆率、光学反射率、光学透射率等数据，分别在85,300和475K处计算了230 ~ 1600nm波长范围内介电常数张量各分量的光谱。从电子结构的角度讨论了克尔效应的物理起源。结果表明，MnBi中的巨大Kerr旋转源于Mn自旋态从3d *向3d *的带间跃迁。(2)关于新锰化合物和/或人工超结构的开发，尚未获得任何显著的数据，该项目仍有待进一步研究。少

1. Magneto-optical effects of rare earth (RE)-transition metal (TM) amorphous alloy films (1) Yb-Co amorphous alloy films are prepared, and the magnetic and magneto-optical properties are measured. It is estimated that the Yb atoms become 2+ ions instead of 3+. As the results, Yb atoms have no magnetic moment in the Yb-Co alloy and the magnetic and magneto-optical properties are very similar to those for La-Co and/or Ce-Co films.(2) The magneto-optical Kerr effect is investigated for Gd-Co films with wide range of Gd content from 10 to 50 atomic percents. Different from other RE species, the atomic moment of Co decreases only slightly with the increase of Gd content, the fact which results in the relatively large Kerr rotation at higher Gd concentration. By analyzing the compositional dependence of the Kerr rotation, the contributions from both Gd and Co sub network magnetizations are separated and the spectra of the Kerr rotation coefficient are determined within the range of waveleng … More th from 400 to 1,000nm.(3) The magnetic structures of RE-TM amorphous alloys except RE=Eu are clarified using all available data including present project studies.(4) The contributions of RE and TM sub networks on the Kerr rotation spectra are separated for RE-Fe_<0.8>Co_<0.2> alloy films, which are important media for magneto-optical memory.2. Studies on the development of new magneto-optical materials of Mn compound and/or multilayrs(1) A remarkable increase of Kerr rotation at low temperature, which cannot be explained by the existing theory, is found for MnBi films. The spectra of all components of dielectric constant tensor are calculated in the wavelength range of 230-1600nm at 85,300, and 475K from the data on the Kerr rotation, the Kerr ellipticity, optical reflectivity, and optical transmittance. The physical origins of the Kerr effect are discussed from the viewpoint of electronic structure. It is concluded that the giant Kerr rotation in MnBi is originated from the interband transition from 3d * to 3d * spin states of Mn.(2) As for the development of new Mn compounds and/or artificial superstructures, any remarkable data have not yet been obtained, and the project is remained for further investigations. Less