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

X-ray diffraction imaging ('X-ray topography') based on Thomson (charge) sc attering 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, us ing the long (150 m) beamline ID 19, devoted to imaging, include: (1) the o bservation of the domains in the low-temperature phase of magnetite, showin g that the actual symmetry is triclinic (2) new results on the unusual magn etization process in hematite (3) the observation of the helimagnetic-ferro magnetic-fan phase coexistence (triple point) in manganese phosphide (4) th e visualization of magneto-acoustic modes in iron borate, with striking var iations in the image as a function of specimen-detector distance and (5) th e imaging, through the inverse piezomagnetic effect, of the 180 anti ferrom agnetic 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.