X線小角散乱法の金属学への応用

抄録

Small-Angle X-Ray Scattering (SAS) has wide application in the field of macromolecules, colloidal solutions etc., while its application to physical metallurgy is restricted. But the smaller particles than 100Å in metals and alloys can be analysed better by the SAS method than by electron microscopy. It was Guinier who first introduced SAS techniques to this field. He had studied the structure of small heterogeneities, named Guinier-Preston Zones. They have the same crystallographic structure as the matrix solid solutions. But it is clear from the theory of SAS that this method can be applied to detect the heterogeneities of atoms in the non-crystalline materials, as glass materials.
The advantage in the application of SAS is the fact that lattice strains cause only minor changes of the diffracted intensity.
In this summarizing report, it is intended to describe what can be clarified by the SAS method. The determination methods of average particle size, particle number, solute concentrations inside and outside particles, size distribution, shape, the concentration gradient at the particle surface and spacial distribution of particles are described with the theoretical background and some examples.
SAS has also been applied to the analysis of lattice defects, as agglomeration of vacancies and dislocations. The scattering intensities with these defects are much weaker than with clusters of solute atoms. As the undesired diffraction effects, double Bragg scattering, incoherent Compton scattering, temperature scattering and fluorescent radiation must be considerd in the quantitative analysis.