The characterization of magnetic bubble-domain materials with X-ray topography

The use of X-ray topography to characterize magnetic bubble materials is discussed. By mapping the crystal strains, the technique reveals defects which can influence the bubble domains and which are not easily observed by other methods. Examples of topographs are given for flux grown iron garnets, Czochralski grown Gd3Ga5O12substrate crystals, and LPE iron garnet layers. The influence of substrate defects on the magnetic film is demonstrated. Transmission topographs of substrate-film combinations have not revealed an intermediate layer of misfit dislocations. The application of X-ray topography to a study of the growth induced anisotropy in magnetic garnets is also described. The topographs reveal a correlation between regions having a particular growth band symmetry and those having a particular noncubic anisotropy.