Xhyphen;ray topographic observations of magnetic domains in Czochralskihyphen;grown nickel single crystals in anomalous transmission geometry

摘要

The anomalous transmission effect has been observed in nickel single crystals grown by the Czochralski technique. Sample crystals prepared for xhyphen;ray topography are 1.5ndash;2.5 cm in diameter and thicker than 0.4 mm; the product of the ordinary linear absorption coefficient and thickness ranges from 17 to 45 for CuKagr; radiation. Topographs taken with an asymmetrichyphen;crystalhyphen;topographic (ACT) camera have revealed extremely straight line images and rectangular arrangements of short linehyphen;segment images, along with the images of crystal imperfections. The line images change their arrangement upon application of magnetic fields. These images are attributed to magnetic domains in the interior of crystals. The formation of domain walls near the crystal surface is also observed and distinguished clearly from magnetic domains in the bulk with the use of the ACT camera.