Nuclear Bragg Diffraction of Synchrotron Radiation in the Presence of Acoustic Vibrations

Ultrasonic standing waves, excited in FeBO3(111) crystal plates through magneto-elastic coupling, were visualized using monochromatic Bragg diffraction imaging (topography) with synchrotron radiation. The images depend strongly on whether diffraction by the sample occurs in the same plane as in the double-crystal monochromator, or in the perpendicular plane. The observations are explained by taking into account (a) the strong spatial dispersion which prevails because of the small effective divergence (angular size of the source as seen from a point in the specimen), which is less than one microradian in this experiment, and (b) the sample vibration and curvature.

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Modeling Valence-Band Images from Synchrotron-Radiation Studies Using Display Analyzers: Lithium Fluoride and Graphite

MRS Proceedings ◽

10.1557/proc-375-151 ◽

1994 ◽

Vol 375 ◽

Author(s):

Eric L. Shirley ◽

Louis J. Terminello ◽

John E. Klepeis ◽

F. J. Himpsel

Keyword(s):

Synchrotron Radiation ◽

Band Structure ◽

Lithium Fluoride ◽

State Energy ◽

Bragg Diffraction ◽

Angular Distributions ◽

Initial State ◽

Statistical Comparison ◽

Photoelectron Angular Distributions ◽

Initial Crystal

AbstractWe present simulated photoelectron angular distributions (PAD's) for LiF and graphite. The results describe electron photocurrent versus photon energy, electron initial-state energy, and emission angles (leading to identification of two, or three, components of a valence electron's initial crystal momentum). Results are displayed in a fashion greatly facilitated by display analyzers. Earlier experimental results for LiF are confirmed in great detail. We discuss statistical comparison of theoretical and experimental PAD's. Effects of Bragg- diffraction on outgoing photoelectrons and uncertainty in crystal momentum normal to a surface are analyzed. In graphite, the observed lowering of symmetry, from that in a periodic-zone band structure to that seen in the PAD's, is modeled and explained.

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Contemporary X-ray electron-density studies using synchrotron radiation

IUCrJ ◽

10.1107/s2052252514018570 ◽

2014 ◽

Vol 1 (5) ◽

pp. 267-280 ◽

Cited By ~ 25

Author(s):

Mads R. V. Jørgensen ◽

Venkatesha R. Hathwar ◽

Niels Bindzus ◽

Nanna Wahlberg ◽

Yu-Sheng Chen ◽

...

Keyword(s):

Synchrotron Radiation ◽

Diffraction Data ◽

Bragg Diffraction ◽

Anomalous Scattering ◽

Future Directions ◽

X Ray ◽

Conventional Radiation ◽

Radiation Sources ◽

Systematic Effects

Synchrotron radiation has many compelling advantages over conventional radiation sources in the measurement of accurate Bragg diffraction data. The variable photon energy and much higher flux may help to minimize critical systematic effects such as absorption, extinction and anomalous scattering. Based on a survey of selected published results from the last decade, the benefits of using synchrotron radiation in the determination of X-ray electron densities are discussed, and possible future directions of this field are examined.

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Monochromatization of synchrotron radiation by ultranarrow frequency filters-nuclear bragg diffraction in yig

Hyperfine Interactions ◽

10.1007/bf02354744 ◽

1986 ◽

Vol 27 (1-4) ◽

pp. 59-67 ◽

Cited By ~ 5

Author(s):

E. Gerdau ◽

R. Rüffer

Keyword(s):

Synchrotron Radiation ◽

Bragg Diffraction

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169Tm-A new candidate for monochromatization of synchrotron radiation by nuclear Bragg diffraction

Hyperfine Interactions ◽

10.1007/bf02398365 ◽

1990 ◽

Vol 58 (1-4) ◽

pp. 2483-2487 ◽

Cited By ~ 2

Author(s):

W. Sturhahn ◽

E. Gerdau ◽

S. Börger ◽

W. Guse

Keyword(s):

Synchrotron Radiation ◽

Bragg Diffraction

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Inception and movement of a `subgrain boundary precursor' in ice under an applied stress, observed by X-ray synchrotron radiation Bragg imaging

Journal of Applied Crystallography ◽

10.1107/s1600576715006342 ◽

2015 ◽

Vol 48 (3) ◽

pp. 672-678 ◽

Cited By ~ 2

Author(s):

A. Philip ◽

L. Capolo ◽

J. Meyssonnier ◽

J. Baruchel

Keyword(s):

Synchrotron Radiation ◽

Basal Slip ◽

Strain State ◽

Applied Load ◽

Subgrain Boundary ◽

Bragg Diffraction ◽

Ice Crystals ◽

X Ray ◽

Integrated Intensity ◽

Diffraction Imaging

Basal slip of dislocations, the easiest deformation mechanism of ice crystals, does not allow a response to any strain state. The first steps of another mechanism, with a moving subgrain boundary precursor region, which permits accommodating the effect of an applied load, is investigated on an ice single crystal, mainly using synchrotron radiation Bragg diffraction imaging. During this process, the evolution of the local integrated intensity shows that there is both a general multiplication of dislocations within the crystal and a movement of basal dislocations towards the surface. The `subgrain boundary precursor' region evolves towards a classical grain boundary when further deformed.

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