Lichtoptisches Präzisions-Orientierungsverfahren für Halbleitereinkristalle

Methods of orientation of semiconducting crystals are classified in connection with their main dates. A new precision method of orientation suitable for materials with good cleavage is described and explained for the orientation of GaAs crystals.     

Aluminiumoxid für technische Anwendungen

A method for preparation of aluminiumhydroxid and alfa and gamma modifications of Al₂O₃ of high chemical purity and suitable physical properties is described. The gamma modification of Al₂O₃ was proved as a starting powder for the preparation of crystals of corundum, and the alfa modification of Al₂O₃ was tested as an effective polishing powder on crystals. With regard to the physical properties and the spherical form of the particles it seems that this aluminiumoxid is useful and perspective for other technical applications too.     

Externe Kristalljustierung für die Lang-Topographie

In dependence on crystal altitude, Bragg angle and distance focus-crystal the necessary accuracy of crystal adjustment is calculated on condition that with illumination of the full crystal height the Kα-doublet is separable. In this connection a critical crystal altitude for the Lang-topography is stated, which requires a faultless adjustment of the net plane. For the real altitude of crystal resp. film adequate demands for adjustment are derived. A simple diffractometer device for external crystal adjustment if described and the attainable accuracy is indicated.     

Betrachtungen zur Struktur aufgedampfter Metallschichten für Widerstandsbauelemente

The possibility of forming two phases or more is a prerequisite for a vapour-deposited metallic layer being suited for manifacturing resistance components for utilization in the field of electrotechnics. The electrotechnic qualities demanded result from such a structure of the layer which deviates from crystalline order. The structure of these layers is an X-ray amorphous one. The optimum electric qualities of resistance components are to be found in a narrow range, situated near crystalline order. Repeatability of layer qualities depends on “hit accuracy” of this structure of layers during production.     

Kontrastsimulationen für die Transmissionselektronenmikroskopie und -beugung mit elektronischen Rechenmaschinen

The paper summarily reports on the computer simulations of diffraction effects caused by fast electrons at multidimensional lattice defects as well as on the output of the results in the form of contrast maps of contrast profiles. Important phenomena of transmission electron diffraction, also accessible to this procedure, are treated likewise. The image structures derived from the theory of electron diffraction in this way are comparable to those, which are observable in thin crystals by transmission electron microscopy and transmission electron diffraction. Introductorily the mathematical and physical starting situation respectively is shortly treated.     

Zur Integration der Grundgleichungen für bewegte Eigenspannungsquellen in kubischen Kristallen

Solutions of the equations of dislocation theory are given being based on a mathematical method which decouples the system of differential equations for the displacement vector. The solutions regard elastic anisotropy of crystalline matter not only in statics but also in dynamics. — The method succeeds in the case of plane strain in cubic or hexagonal crystals, allowing most general plastic distorsions as well as processes of arbitrary timedependence. Decoupling is the basis for using complex variable methods which may be applied when dislocations move in a uniform way.     

Ableitung der Verteilung von Kornlängen für drei einfache eindimensionale Erstarrungsprozesse

At first in this theoretical article a melt in a capillary tube is considered, when appearing a number of nuclei by undercooling. The distribution function of the distances between neighbouring nuclei is deduced by use of the theory of stochastic processes. The average of these distances is the parameter in the distribution function. Under this supposition for the nuclei-distances the distribution functions of the length of crystals, forming by three different ways of crystallization in the capillary tube, is deduced.