Symposium on discontinuous films,Nal'chik,U.S.S.R., 8–13 April, 1976

The dislocation structure in an InGaAs/GaAs heterojunction with an epilayer thickness of 8 μm and a misfit of 0.003 was studied by X-ray topographic techniques. Misorientations in the approximately square cross-grid of dislocations permit the three-dimensional nature of the dislocation structure in the epilayer to be studied. The evidence presented here suggests that a source other than one of those previously favored is the dominant contributor to the interfacial dislocation structure; the most likely possibility is that the majority of dislocations are introduced at sources created by interactions of gliding threading dislocations.     

Röntgenographische Untersuchung von Spannungszuständen in Werkstoffen Teil IV. Fortsetzung von Matwiss. und Werkstofftechn. Heft 3/1995, S. 148–160, Heft 4/1995, S. 199–216 und Heft 9/1996, S. 426–437

X-Ray Investigation of Stress States in Materials X-ray stress analyses of crystalline or partially crystalline materials are based on the determination of elastic lattice strains which are converted to stresses by means of theory of elasticity. The development of the sin²Ψ-method of X-ray stress analysis and of diffractometers substituting film chambers during the 1960s initiated an enormous progress in X-ray stress analysis during the following three decades both in respect of the knowledge of the underlying principles and in respect of the practical application. This report sketches the historical development of X-ray stress analyses and describes the actual state of the art of this important tool for materials science and engineering. Besides some important elements of X-ray physics and theory of elasticity, experimental aspects of practical applications are outlined. Standard measuring procedures and special measuring problems are described and hints for practical solutions are given. In particular, examples of destructive and non-destructive depth profiling of residual stresses of residual stress analyses in thin coatings, in multilayer structures of thin coatings and in chemically graded coatings, of residual stress analyses in presence of textures, of residual and loading stress analyses in heterogeneous materials, in coarse grained, and in single crystalline materials are presented. The methods established up to now are explained and possible future developments are pointed out.