Studies of mesoscopic structures with synchrotron X-rays

利用高分辨率同步x射线散射技术研究了机械熔合粉末、金属玻璃和磁性多层材料中的介观结构。结果表明，不同热处理条件下，球磨粉的介观结构发生了不同程度的变化。球磨TiAl是高度无序的合金相，退火后转变为TiAl_3结晶相。FeSiBCuNb纳米晶合金的x射线粉末数据表明，其磁导率比传统的FeSiBCuNb纳米晶合金有所提高。采用不同热处理条件下的样品，研究了其结构与性能的相关性。磁性材料方面，利用x射线共振磁散射技术研究了Fe/Gd多层材料的磁化结构。结果表明，5nm厚的Gd层在排列态和扭曲态下都是不均匀磁化的。在排列态下，Gd层在Fe界面附近比在薄膜中心处磁化更强。当温度低于补偿温度30℃时，Gd磁矩的扭转角在薄膜厚度上也不均匀，且垂直于外加磁场。

Mesoscopic structures in mechanofusion powders, metal glasses and magnetic multilayrs have been investigated using high-resolution synchrotron X-ray scattering techniques. It was revealed that the mesoscopic structures in ball-milled Fen powder undergo a wide variety of changes depending on heattreatment conditions. Ball-milled TiAl involves highly disordered alloy phases which change into the TiAl_3 crystalline phase on annealing. X-ray powder data were collected from FeSiBCoCuNb nanocrystalline alloy, which shows an improved magnetic permeability over conventional finemet (FeSiBCuNb). The structure/property correlation was investigated by using samples annealed in various conditions. As to the magnetic materials, the magnetization structures of Fe/Gd multilayrs were explored using the resonant X-ray magnetic scattering technique. It was made clear that 5 nmthick Gd layrs are nonuniformly magnetized in both the aligned and twisted states. In the aligned state, the Gd layrs are more strongly magnetized near the Fe interfaces than at the film centers. The twist angle of the Gd magnetic moment in the twisted state is also nonuniform over the film thickness and it is perpendicular to the applied magnetic field at a temperature 30ﾟC below the compensation temperature.