Concurrent deep UV diffractions enabled by the Bragg condition and crystal symmetry in silica inverse opals

In the Study of small metal particles the shape is a very Important parameter. Using electron microscopy Ino and Owaga(l) have studied the shape of twinned particles of gold. In that work electron diffraction and contrast (dark field) experiments were used to produce models of a crystal particle. In this work we report a method which can give direct information about the shape of an small metal particle in the amstrong- size range with high resolution. The diffraction pattern of a sample containing small metal particles contains in general several systematic and non- systematic reflections and a two-beam condition can not be used in practice. However a N-beam condition produces a reduced extinction distance. On the other hand if a beam is out of the bragg condition the effective extinction distance is even more reduced.

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Spacings and Intensities of Weak-Beam Dark Field Thickness Fringes

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100097685 ◽

1981 ◽

Vol 39 ◽

pp. 222-223

Author(s):

M. Avalos-Borja ◽

K. Heinemann

Keyword(s):

Selection Criterion ◽

Dark Field ◽

Dynamical Theory ◽

Bragg Condition ◽

Weak Beam ◽

Kinematical Theory ◽

Equal Thickness

Weak-beam dark field (WBDF) TEM produces narrowly spaced equal-thickness fringes in wedge-shaped crystals. Using non-systematic diffraction conditions, we have shown elsewhere that simple 2-beam kinematical theory (KT) calculations yield average fringe spacings that are for most practical purposes as satisfactorily accurate as the average spacings obtained from optimized multibeam dynamical theory (DT) calculations, As Fig. 1 shows, this result holds for deviations from the Bragg condition as low as 2x10-1 nm-1, and the differences between the results from the two calculational methods become increasingly insignificant for larger excitation errors. (Unless otherwise noted, all results reported here are for gold crystals, using the 200 beam at 100 KV; the DT calculations were made for 74 beams, using the selection criterion D as discussed in ref. [3]).

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Microstructure and crystal symmetry of Pb2Sr2(Y/Ca)Cu3O9−δ

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100173455 ◽

1990 ◽

Vol 48 (4) ◽

pp. 64-65

Author(s):

Y. P. Lin ◽

J. S. Xue ◽

J. E. Greedan

Keyword(s):

Electron Diffraction ◽

High Temperature Superconductors ◽

Carbon Film ◽

Basic Structure ◽

Crystal Symmetry ◽

X Ray Diffraction ◽

X Ray ◽

Space Groups ◽

New Family ◽

Convergent Beam

A new family of high temperature superconductors based on Pb2Sr2YCu3O9−δ has recently been reported. One method of improving Tc has been to replace Y partially with Ca. Although the basic structure of this type of superconductors is known, the detailed structure is still unclear, and various space groups has been proposed. In our work, crystals of Pb2Sr2YCu3O9−δ with dimensions up to 1 × 1 × 0.25.mm and with Tc of 84 K have been grown and their superconducting properties described. The defects and crystal symmetry have been investigated using electron microscopy performed on crushed crystals supported on a holey carbon film.Electron diffraction confirmed x-ray diffraction results which showed that the crystals are primitive orthorhombic with a=0.5383, b=0.5423 and c=1.5765 nm. Convergent Beam Electron Diffraction (CBED) patterns for the and axes are shown in Figs. 1 and 2 respectively.

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Multislice calculations of RHEED patterns from vicinal Si (001)

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100150836 ◽

1993 ◽

Vol 51 ◽

pp. 1000-1001

Author(s):

Scott Lordi

Keyword(s):

Misorientation Angle ◽

Incident Angle ◽

Incident Beam ◽

Experimental Results ◽

Bragg Condition ◽

Vicinal Surfaces ◽

Kinematic Theory ◽

Step Edges

Vicinal Si (001) surfaces are interesting because they are good substrates for the growth of III-V semiconductors. Spots in RHEED patterns from vicinal surfaces are split due to scattering from ordered step arrays and this splitting can be used to determine the misorientation angle, using kinematic arguments. Kinematic theory is generally regarded to be inadequate for the calculation of RHEED intensities; however, only a few dynamical RHEED simulations have been attempted for vicinal surfaces. The multislice formulation of Cowley and Moodie with a recently developed edge patching method was used to calculate RHEED patterns from vicinal Si (001) surfaces. The calculated patterns are qualitatively similar to published experimental results and the positions of the split spots quantitatively agree with kinematic calculations.RHEED patterns were calculated for unreconstructed (bulk terminated) Si (001) surfaces misoriented towards [110] ,with an energy of 15 keV, at an incident angle of 36.63 mrad ([004] bragg condition), and a beam azimuth of [110] (perpendicular to the step edges) and the incident beam pointed down the step staircase.

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Development of Silicon Wafer Packaging Technology for Deep UV LED

IEEJ Transactions on Sensors and Micromachines ◽

10.1541/ieejsmas.140.152 ◽

2020 ◽

Vol 140 (7) ◽

pp. 152-157

Author(s):

Hirofumi Chiba ◽

Yukio Suzuki ◽

Yoshiaki Yasuda ◽

Mitsuyasu Kumagai ◽

Takaaki Koyama ◽

...

Keyword(s):

Silicon Wafer ◽

Packaging Technology ◽

Uv Led ◽

Deep Uv

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PULSED UV IRRADIATION USING DEEP UV-LED FOR INACTIVATION OF ESCHERICHIA COLI

Journal of Japan Society of Civil Engineers Ser G (Environmental Research) ◽

10.2208/jscejer.75.7_iii_91 ◽

2019 ◽

Vol 75 (7) ◽

pp. III_91-III_96

Author(s):

Tomoyasu SADO ◽

Kumiko OGUMA ◽

Takashi HASHIMOTO ◽

Shinobu KAZAMA ◽

Satoshi TAKIZAWA

Keyword(s):

Escherichia Coli ◽

Uv Irradiation ◽

Uv Led ◽

Deep Uv

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Infrared spectroscopic study of the YPO4-YCrO4 system

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19852139 ◽

1985 ◽

Vol 50 (10) ◽

pp. 2139-2145

Author(s):

Alexander Muck ◽

Eva Šantavá ◽

Bohumil Hájek

Keyword(s):

Spectroscopic Study ◽

Infrared Spectra ◽

Point Of View ◽

Mixed Crystals ◽

Crystal Symmetry ◽

Infrared Spectroscopic Study ◽

X Ray Diffraction ◽

X Ray ◽

Infrared Spectroscopic ◽

Diffraction Patterns

The infrared spectra and powder X-ray diffraction patterns of polycrystalline YPO4-YCrO4 samples are studied from the point of view of their crystal symmetry. Mixed crystals of the D4h19 symmetry are formed over the region of 0-30 mol.% YPO4 in YCrO4. The Td → D2d → D2 or C2v(GS eff) correlation is appropriate for both PO43- and CrO43- anions.

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