Radiation of X-rays in Low-Pressure Gas Using LiNbO<sub>3</sub> Single Crystal

In an earlier paper (Sakata et al., 1989), it was shown that the 4th and 6th order ODF coefficients could be successfully derived from Young's modulus measurements using the elastic energy method. However, the values of some of the coefficients fell beyond the expected error ranges. In this study, more appropriate single crystal elastic constants are selected by means of a fitting procedure. Then the ODF coefficients are again estimated in the manner described previously. As a result, the values of the C411, C611, C612 and C614 coeffioents, which were somewhat inaccurate in the previous calculation, are improved considerably. The volume fractions of the principal preferred orientations are then employed to predict the 8th order coefficients and the fiber components of the l = 10 and l = 12 (C1011, C1211 and C1221) coefficients. With the aid of the coefficients obtained in this way, both pole and inverse pole figures are drawn, which are in better agreement with those based on X-rays than when only the 4th order coefficients are employed.

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Lower resolution Laue neutron data yield correct nanocluster formulations

Acta Crystallographica Section A Foundations and Advances ◽

10.1107/s205327331409812x ◽

2014 ◽

Vol 70 (a1) ◽

pp. C187-C187

Author(s):

Alison Edwards

Keyword(s):

Neutron Diffraction ◽

Single Crystal ◽

Diffraction Pattern ◽

Precise Determination ◽

Data Sets ◽

X Rays ◽

Low Resolution ◽

Neutron Data ◽

X Ray ◽

Product Formulation

"The renaissance in Laue studies - at neutron sources - provides us with access to single crystal neutron diffraction data for synthetic compounds without requiring synthesis of prohibitively large amounts of compound or improbably large crystals. Such neutron diffraction studies provide vital data where proof of the presence or absence of hydrogen in particular locations is required and which cannot validly be proved by X-ray studies. Since the commissioning of KOALA at OPAL in 2009[1] we have obtained numerous data sets which demonstrate the vital importance of measuring data even where the extent of the diffraction pattern is at relatively low resolution - especially when compared to that obtainable for the same compound with X-rays. In the Laue experiment performed with a fixed radius detector, data reduction is only feasible for crystals in the ""goldilocks"" zone – where the unit cell is relatively large for the detector, a correspondingly low resolution diffraction pattern in which adjacent spots are less affected by overlap will yield more data against which a structure can be refined than a pattern of higher resolution – one where neighbouring spots overlap rendering both unusable (in our current methodology). Analogous application of powder neutron diffraction in such determinations is also considered. Single crystal neutron diffraction studies of several important compounds (up to 5KDa see figure below)[2] in which precise determination of hydride content by neutron diffraction was pivotal to the final formulation will be presented. The neutron data sets typically possess 20% or fewer unique data at substantially "lower resolution" than the corresponding X-ray data sets. Careful refinement clearly reveals chemical detail which is typically unexplored in related X-ray diffraction studies reporting high profile chemistry despite the synthetic route being one which hydride ought to be considered/excluded in product formulation."

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Deformation of single crystal sample using D-DIA apparatus coupled with synchrotron X-rays: In situ stress and strain measurements at high pressure and temperature

Journal of Physics and Chemistry of Solids ◽

10.1016/j.jpcs.2010.03.005 ◽

2010 ◽

Vol 71 (8) ◽

pp. 1053-1058 ◽

Cited By ~ 12

Author(s):

Jennifer Girard ◽

Jiuhua Chen ◽

Paul Raterron ◽

Caleb Holyoke

Keyword(s):

High Pressure ◽

Single Crystal ◽

In Situ Stress ◽

Single Crystal Sample ◽

Stress And Strain ◽

X Rays ◽

Crystal Sample ◽

High Pressure And Temperature ◽

Strain Measurements

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Single crystal diffraction with X-rays and neutrons: High quality at high pressure?

High Pressure Research ◽

10.1080/08957959608201420 ◽

1996 ◽

Vol 14 (4-6) ◽

pp. 341-352 ◽

Cited By ~ 15

Author(s):

W. F. Kuhs ◽

F. C. Bauer ◽

R. Hausmann ◽

H. Ahsbahs ◽

R. Dorwarth ◽

...

Keyword(s):

High Pressure ◽

Single Crystal ◽

X Rays ◽

High Quality ◽

Single Crystal Diffraction

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A single crystal, linearly polarized Fe 2p X-ray absorption study of gillespite

Mineralogical Magazine ◽

10.1180/002646198547477 ◽

1998 ◽

Vol 62 (1) ◽

pp. 65-75 ◽

Cited By ~ 7

Author(s):

P. F. Schofield ◽

G. van der Laan ◽

C. M. B. Henderson ◽

G. Cressey

Keyword(s):

Single Crystal ◽

Ground State ◽

Branching Ratio ◽

Linear Dichroism ◽

Electronic Charge ◽

Magic Angle ◽

X Rays ◽

X Ray ◽

Peak Structure ◽

X Ray Absorption

AbstractThe Fe 2p X-ray absorption spectra of single crystal gillespite, BaFeSi4O10, show a strong linear dichroism, i.e. a large difference in the absorption when measured with the polarization of the X-rays either parallel or perpendicular to the plane of the FeO4 group. The isotropic spectrum, obtained from measurement at the ‘magic angle’, and the polarization dependent spectra have been compared to atomic multiplet calculations and show an excellent agreement with theory. Analysis of the branching ratio, the linear dichroism, and the detailed peak structure confirms that the 5A1 level is the ground state at room temperature and pressure. The 5B2 level is sufficiently low in energy that a distortion of the electronic charge density, induced by increased pressure, may result in a 5B2 ground state.

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SURFACE SEGREGATION STUDIES OF SOFC CATHODES: COMBINING SOFT X-RAYS AND ELECTROCHEMICAL IMPEDENCE SPECTROSCOPY

MRS Proceedings ◽

10.1557/proc-1217-y07-04 ◽

2009 ◽

Vol 1217 ◽

Author(s):

Lincoln Miara ◽

Louis Piper ◽

Jacob Nathan Davis ◽

Laxmikant Saraf ◽

Tiffany Kaspar ◽

...

Keyword(s):

Single Crystal ◽

Surface Segregation ◽

Elevated Temperatures ◽

Electrochemical Impedance ◽

Lanthanum Manganite ◽

X Rays ◽

Two Phase ◽

X Ray ◽

Cation Migration ◽

X Ray Absorption

AbstractA system to grow heteroepitaxial thin-films of solid oxide fuel cell (SOFC) cathodes on single crystal substrates was developed. The cathode composition investigated was 20% strontium-doped lanthanum manganite (LSM) grown by pulsed laser deposition (PLD) on single crystal (111) yttria-stabilized zirconia (YSZ) substrates. By combining electrochemical impedance spectroscopy (EIS) with x-ray photoemission spectroscopy (XPS) and x-ray absorption spectroscopy XAS measurements, we conclude that electrically driven cation migration away from the two-phase gas-cathode interface results in improved electrochemical performance. Our results provide support to the premise that the removal of surface passivating phases containing Sr2+ and Mn2+, which readily form at elevated temperatures even in O2 atmospheric pressures, is responsible for the improved cathodic performance upon application of a bias.

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