Using a triple-crystal arrangement, the CuKalpha (111) and (333) X-ray reflection curves of dislocation-free Ge and Si have been measured in the symmetric and asymmetric Bragg case. Comparison with the corresponding curves derived from the Dynamical Theory of Ewald and v. Laue with consideration of absorption exhibits excellent coincidence of experimental and theoretical curves. In particular, the observed asymmetry of the reflection curves, resulting from absorption, is reproduced and fully explained by the theory.

Using a triple-crystal arrangement, the Cu K α (111) and (333) X-ray reflection curves of dislocation-free Ge and Si have been measured in the symmetric and asymmetric Bragg case. Comparison with the corresponding curves derived from the Dynamical Theory of Ewald and v. Laue with consideration of absorption exhibits excellent coincidence of experimental and theoretical curves. In particular, the observed asymmetry of the reflection curves, resulting from absorption, is reproduced and fully explained by the theory.

The results are presented of the experimental and theoretical study of a coplanar four-beam x-ray diffraction by a large Ge single crystal. The planes employed are [440, 260, and 220] or [220, 260 and 440] and the four-beam diffraction is of the Bragg-Laue type. An apparent anomaly is found on the double-crystal (n1, +n2) rocking curve when the coplanar four-beam diffraction occurs on the second crystal. The experimental and theoretical results are in good agreement. Es werden die Ergebnisse einer experimentellen und theoretischen Untersuchung einer koplanaren Vierstrahl-Röntgenbeugung mittels eines großen Ge-Einkristalls mitgeteilt. Die verwendeten Ebenen sind [440, 260 und 220] oder [220, 260 und 440] und die Vierstrahlbeugung ist vom Bragg-Laue-Typ. An der Doppelkristall(n1, +n2)-Rockingkurve tritt eine Anomalie auf, wenn die koplanare Vierstrahlbeugung am zweiten Kristall auftritt. Die experimentellen und theoretischen Ergebnisse sind in guter Übereinstimmung.

The peak of the spectral line Ni Kα2 was measured by the double-crystal spectrometer in the arrangement (Si 440 sym., +Si 440 sym.). It is possible to adjust the Si crystal so that the conditions for coplanar three-beam Si[000, 440, 404] diffraction are satisfied for the wavelength of the incident radiation λ ~ 0.166288 nm involved in the Ni Kα2 peak. When the second Si crystal was adjusted to this three-beam diffraction position an anomalous change of the measured dependence was found. A very simple model of the experiment was suggested and the necessary calculation completing the paper of Graeff & Bonse [Z. Phys. B, (1977), 27, 19-32] was performed to explain qualitatively the anomalous change.

The calculated intensities of the X-ray beam behind the exit surface of the Ge [440, {\bar 2}20] dispersive monolithic monochromator for Co Kα1 radiation are presented. The reflections 440 and {\bar 2}20 resulting from Ge {000, 440, 260, {\bar 2}20} coplanar four-beam diffraction were taken into account and the influence of the π/2 reflection 260 is discussed. The four-surface arrangement of Ge [440, {\bar 2}20] providing the resultant beam parallel to the incident beam is considered. For comparison Ge [440, {\bar 2}20] in the two-beam approximation is solved. The obtained results demonstrate that the four-beam basis of diffraction affects the resultant beam. The quality of the X-ray beam evaluated behind the examined monochromators also provided the conditions for the use of such monochromators as wavelength standards.

Abstract The absorption effect in dispersion and reflection curves is shown for the a and n polarizations and for some wavelengths in the small wavelength interval in which the coplanar four-beam diffraction of x-rays exists. The investigated coplanar Ge[000, 440, 260, 2̄20] reflections appear in a Ge[440, 2̄20] monolithic monochromator working with CoKα1 radiation. It is shown that the absorption not only reduces the intensity in a complicated way but also changes the energy distribution between the participating reflections.

physica status solidi (a)Volume 74, Issue 1 p. 107-112 Original Paper Co Containing Garnet Films with Low Magnetization P. Görnert, P. Görnert Physikalisch-Technisches Institut der Akademie der Wissenschaften der DDR, Jena Search for more papers by this authorM. Nevřiva, M. Nevřiva Institute of Physics, Czechoslovak Academy of Sciences, PragueSearch for more papers by this authorJ. Šimšová, J. Šimšová Research Institute of Mathematical Machines, PragueSearch for more papers by this authorW. Andrä, W. Andrä Institute of Physics, Czechoslovak Academy of Sciences, PragueSearch for more papers by this authorW. Schüppel, W. Schüppel Physikalisch-Technisches Institut der Akademie der Wissenschaften der DDR, Jena Search for more papers by this authorP. Šumšál, P. Šumšál Physikalisch-Technisches Institut der Akademie der Wissenschaften der DDR, Jena Search for more papers by this authorR. Bubáková, R. Bubáková Institute of Physics, Czechoslovak Academy of Sciences, PragueSearch for more papers by this author P. Görnert, P. Görnert Physikalisch-Technisches Institut der Akademie der Wissenschaften der DDR, Jena Search for more papers by this authorM. Nevřiva, M. Nevřiva Institute of Physics, Czechoslovak Academy of Sciences, PragueSearch for more papers by this authorJ. Šimšová, J. Šimšová Research Institute of Mathematical Machines, PragueSearch for more papers by this authorW. Andrä, W. Andrä Institute of Physics, Czechoslovak Academy of Sciences, PragueSearch for more papers by this authorW. Schüppel, W. Schüppel Physikalisch-Technisches Institut der Akademie der Wissenschaften der DDR, Jena Search for more papers by this authorP. Šumšál, P. Šumšál Physikalisch-Technisches Institut der Akademie der Wissenschaften der DDR, Jena Search for more papers by this authorR. Bubáková, R. Bubáková Institute of Physics, Czechoslovak Academy of Sciences, PragueSearch for more papers by this author First published: 16 November 1982 https://doi.org/10.1002/pssa.2210740112Citations: 15 Helmholtzweg 4, DDR-6900 Jena, GDR. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinkedInRedditWechat Abstracten Epitaxial Co containing YIG films with higher substitutions of Ca2+–Ge4+ ions and therefore lower magnetization than in previous investigations are deposited on {111}, {100}, and {110} GGG substrates. The dependence of some magnetic parameters (magnetization, bubble-collapse field, coercive force, effective crystal anisotropy constant) on film composition is determined. The magnetic domain structure depends on these parameters and the film orientation. Abstractde Epitaktische cobalthaltige YIG-Schichten mit stärkeren Substitutionen durch Ca2+–Ge4+-Ionen und deshalb niedrigerer Magnetisierung als bei früheren Untersuchungen werden auf {111}-, {100}- und {110}-GGG-Substraten abgeschieden. Es wird die Abhängigkeit einiger ihrer magnetischen Parameter (Magnetisierung, Bubble-Kollaps-Feld, Koerzitivfeldstärke, effektive Kristallanisotropiekonstante) von der Schichtzusammensetzung bestimmt. Die magnetische Bereichsstruktur hängt von diesen Parametern und der Schichtzusammensetzung ab. References 1 J. Šimšová, I. Tomáš, P. Görnert, M. Nevřiva and M. Maryško, phys. stat. sol. (a) 53, 297 (1979). 10.1002/pssa.2210530134 Web of Science®Google Scholar 2 I. Tomáš, J. Šimšová, R. Bubáková and M. Maryško, phys. stat. sol. (a) 60, K1 (1980). 10.1002/pssa.2210600140 Web of Science®Google Scholar 3 J. Šimšová, S. Krupićka, M. Maryško and I. Tomáš, Acta phys. Slov. 31, 121 (1981). Web of Science®Google Scholar 4 I. Tomáš, J. Kaczér and L. Murtinová, to be published. Google Scholar 5 P. Görnert, S. Bornmann, F. Voigt and M. Wendt, phys. stat. sol. (a) 41, 505 (1977). 10.1002/pssa.2210410221 Web of Science®Google Scholar 6 W. Andrä, phys. stat. sol. 1, K135 (1961). 10.1002/pssb.19610010613 Web of Science®Google Scholar 7 Z. Šimša, Proc. VII. Conf. Czech. Phys., Prague 1981, Academia Praha (p. 0709) (in Czech). Google Scholar 8 M. D. Sturge, E. M. Gyorgy, R. C. LeCraw and J. P. Remeika, Phys. Rev. 180, 413 (1969). 10.1103/PhysRev.180.413 CASWeb of Science®Google Scholar 9 J. Šimšová and M. Maryško, Proc. V. Conf. Thin Films, Dům Techniky ČSVTS, Plzeň 1980 (p. 136) (in Czech). Google Scholar 10 J. Kaczér, phys. stat. sol. (a) 63, K87 (1981). 10.1002/pssa.2210630170 Web of Science®Google Scholar 11 J. F. Dillon, Jr., J. appl. Phys. 29, 1286 (1958). 10.1063/1.1723427 CASWeb of Science®Google Scholar 12 A. Maziewski, to be published. Google Scholar Citing Literature Volume74, Issue116 November 1982Pages 107-112 ReferencesRelatedInformation

Pure edge dislocations perpendicular to the silicon crystal surface are studied by the double crystal spectrometer X-ray topographic technique in the Bragg case. The diffracting planes are perpendicular to the dislocation line. The bulk strain tensor gives then no contrast in the topograph. However stress relaxation deformations at the intersections of the dislocations with the crystal surface give contrasts which are studied both, experimentally and theoretically. Expermental topographs are compared with theoretical image simulations. Mit der röntgentopographischen Methode des Doppelkristallspektrometers werden im Bragg-Fall reine Stufenversetzungen senkrecht zur Oberfläche eines Siliziumeinkristalles untersucht. Die beugenden Ebenen stehen senkrecht zur Versetzungslinie. Der Spannungstensor im Innern des Kristalls gibt dann keinen Kontrast im Topogramm. Aber aus der Deformation, die durch die Spannungsrelaxation in den Schnittpunkten der Versetzungen mit der Kristalloberfläche verursacht wird, folgt ein Kontrast, der experimentell und theoretisch untersucht wird. Die experimentellen Topogramme werden mit den theoretischen, simulierten verglichen.

physica status solidi (a)Volume 60, Issue 1 p. K1-K3 Short Note Influence of the stress induced anisotropy on the domain structure of YIG: Co films I. Tomáš, I. Tomáš Institue of Physics, Czechoslovak Academy of Sciences, Prague Search for more papers by this authorJ. Šimšová, J. Šimšová Institue of Physics, Czechoslovak Academy of Sciences, Prague Search for more papers by this authorR. Bubáková, R. Bubáková Institue of Physics, Czechoslovak Academy of Sciences, Prague Search for more papers by this authorM. Maryško, M. Maryško Institue of Physics, Czechoslovak Academy of Sciences, Prague Search for more papers by this author I. Tomáš, I. Tomáš Institue of Physics, Czechoslovak Academy of Sciences, Prague Search for more papers by this authorJ. Šimšová, J. Šimšová Institue of Physics, Czechoslovak Academy of Sciences, Prague Search for more papers by this authorR. Bubáková, R. Bubáková Institue of Physics, Czechoslovak Academy of Sciences, Prague Search for more papers by this authorM. Maryško, M. Maryško Institue of Physics, Czechoslovak Academy of Sciences, Prague Search for more papers by this author First published: 16 July 1980 https://doi.org/10.1002/pssa.2210600140Citations: 10 Na Slovance 2, 18040 Prague 8 - Libeň, CSSR. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume60, Issue116 July 1980Pages K1-K3 RelatedInformation

A short view of possible use of a double crystal spectrometer for problems of defect structure of crystals is given. Some results are demonstrated.

The experimental X-ray intensity distribution for the dislocation image is compared with the theoretical one in the symmetrical Bragg case. The considered dislocation is a 30° dislocation perpendicular to the surface of the silicon crystal. Experimental results are obtained using a double crystal spectrometer. The calculated intensity distributions are found solving Takagi's equations. Die im symmetrischen Bragg-Fall der Röntgenstrahlinterferenzen erhaltenen Photographien von 30°-Versetzungen werden mit theoretischen Interferenzbildern verglichen. Die untersuchten Versetzungen liegen senkrecht zur Oberfläche einer Siliziumplatte. Die Photographien werden mit Hilfe eines Doppelkristallspektrometers gewonnen. Die theoretische Intensitätsverteilung in den Interferenzbildern der Versetzung wird aus der Lösung der Takagi-Gleichungen berechnet.

In the image of the 30° dislocation in a silicon single crystal taken in the symmetrical Bragg case of X-ray diffraction an interference phenomenon is observed. The contrast produced by the pure edge dislocations is also noticed. All dislocations considered are perpendicular to the surface of the crystal plate. The topographs are taken by means of a double crystal spectrometer using the MoKα1 radiation. The method is extended by the exposure of the dislocation image simultaneously in the reflected and transmitted beams in the Bragg case. In der röntgenographischen Abbildung einer 30°-Versetzung im Silizium-Einkristall wird im symmetrischen Bragg-Fall ein Interferenzphänomen beobachtet. Der durch eine reine Stufenversetzung verursachte Kontrast ist auch bemerkbar. Alle in Betracht gezogenen Versetzungen laufen senkrecht zur Oberfläche durch den Kristall. Die Topogramme werden durch die Anwendung eines Doppelkristallspektrometers mit MoKα1-Strahlung registriert. Die Methode wird erweitert durch die Exposition eines Versetzungsbildes gleichzeitig im Reflexions- und Transmissions-Strahl.

In the Bragg case of X-ray diffraction the image of the dislocations with large screw component is examined. It is shown that the traditional white-black contrast is completed with an additional narrow black contrast. The experiments were performed by means of the double crystal spectrometer. The CuKα radiation and silicon single crystals were used.

The influence of the presence of parallel component of polarization on the shape of the rocking curves was proved experimentally in the Bragg case of the 220 reflection of silicon. A kink appeared in a reproducible way on the steep part of the rocking curves.

A simple theoretical model is given for the diffraction of X-rays on a perfect crystal with uneven surface. It is assumed that the crystal surface can be approximated by a system of small surfaces, variously inclined from the diffraction planes, and that the diffraction can be calculated as the superposition of independent diffractions from the different small surfaces. The model was verified experimentally by measuring a perfect germanium crystal with an uneven surface on a triple-crystal diffractometer. The unevenness of the surface was studied by optical measurement. Very good agreement with theory was obtained.

AbstractAn X‐ray study is made of a single crystal of Si after irradiation by protons of energy ⋍ 6.5 MeV, the total dose being 1 to 2 × 1018 protons/cm2. An increase of the lattice parameter: Δa ⋍ + 3 × 10−5 Å is observed after bombardment. The atomic planes in the bombarded part of the Si crystal are tilted, making an angle of 1.7″ with planes of the unbombarded part. An imperfection in the diamond‐type structure is found as confirmed by diffraction from the (222) planes.

A description is given of the rapid adjustment of the normals of monocrystal lattice planes for exact measurements on X-ray equipment with two or more crystals. It is estimated with what accuracy the normals of the lattice planes must lie in one plane perpendicular to the axes of rotation of the crystals on a two-crystal spectrometer in the (n, −n) position. The paper describes the equipment by which adjustment can be performed rapidly and with sufficient accuracy.