Cryogenic X-ray topography using synchrotron radiation

The application of synchrotron radiation to low-temperature X-ray topographic studies of magnetic materials is described. Details of four successful cryostat designs are presented. It is demonstrated that because of the peculiar properties of synchrotron radiation, X-ray topography at liquid-nitrogen temperature is extremely easy and work down to liquid-helium temperature straightforward. In addition the specimen may be surrounded by other apparatus, in this case an electromagnet, without appreciable loss of resolution. Topographs of antiferromagnetic domains in KNiF₃ and KCoF₃ are presented, and the first observations by X-ray topography of ferromagnetic domains in a rare-earth metal (terbium) and Jahn-Teller domains in DyVO₄ are reported.