Studies of mesoscopic structures with synchrotron X-rays

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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.