HIGH-Q-RESOLUTION X-RAY-DIFFRACTION OF ORDERED FE-AL SINGLE-CRYSTALS

The use of synchrotron radiation in the study of ordering transitions is presented. The peak-profile measurements can be carried out with a resolution one order of magnitude better than with classical sources i n all directions of the reciprocal lattice. In the case of Fe-Al alloy s, the small-angle scattering techniques can be transposed in the vici nity of a Bragg superstructure peak, which provides information on the antiphase configuration of the ordered alloys. Moreover, the high bri lliance of the undulator of the ESRF ID10 beamline enables coherent sc attering experiments. The conditions necessary to record holograms fro m an inhomogeneous sample are discussed and some results are presented .