Bragg-diffraction imaging of magnetic crystals with third-generation synchrotron radiation

X-ray diffraction imaging ('X-ray topography') based on Thomson (charge) scattering provides information on the magnetic moments if their arrangement entails a variation in distortion. Recent results obtained on high-quality magnetic single crystals at the European synchrotron radiation facility, using the long (150 m) beamline ID 19, devoted to imaging, include: (1) the observation of the domains in the low-temperature phase of magnetite, showing that the actual symmetry is triclinic (2) new results on the unusual magnetization process in hematite (3) the observation of the helimagnetic-ferromagnetic-fan phase coexistence (triple point) in manganese phosphide (4) the visualization of magneto-acoustic modes in iron borate, with striking variations in the image as a function of specimen-detector distance and (5) the imaging, through the inverse piezomagnetic effect, of the 180 anti ferromagnetic domains in cobalt fluoride and of memory effects. The possible new applications of these techniques are discussed. (C) 2001 Elsevier Science B.V. All rights reserved.