SYNCHROTRON RADIATION CHARACTERIZATION OF COBALT NANOPARTICLES FORMED BY ION IMPLANTATION

The implementation of 3-Dimensional X-Ray Diffraction (3DXRD) Microscopy at the Advanced Photon Source is described. The technique enables the non-destructive structural characterization of polycrystalline bulk materials and is therefore suitable for in situ studies during thermo-mechanical processing. High energy synchrotron radiation and area detectors are employed. First, a forward modeling approach for the reconstruction of grain boundaries from high resolution diffraction images is described. Second, a high resolution reciprocal space mapping technique of individual grains is presented.

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Fourier transform infra-red characterization of carbon onions produced by carbon-ion implantation

Chemical Physics Letters ◽

10.1016/s0009-2614(98)00020-7 ◽

1998 ◽

Vol 285 (3-4) ◽

pp. 216-220 ◽

Cited By ~ 19

Author(s):

T. Cabioc'h ◽

A. Kharbach ◽

A. Le Roy ◽

J.P. Rivière

Keyword(s):

Fourier Transform ◽

Ion Implantation ◽

Carbon Ion ◽

Infra Red ◽

Carbon Onions

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Crystallization and preliminary X-ray characterization of the 2,4′-dihydroxyacetophenone dioxygenase fromAlcaligenessp. 4HAP

Acta Crystallographica Section F Structural Biology Communications ◽

10.1107/s2053230x14009649 ◽

2014 ◽

Vol 70 (6) ◽

pp. 823-826 ◽

Cited By ~ 4

Author(s):

G. Beaven ◽

A. Bowyer ◽

P. Erskine ◽

S. P. Wood ◽

A. McCoy ◽

...

Keyword(s):

Synchrotron Radiation ◽

Formic Acid ◽

Molecular Oxygen ◽

Aromatic Ring ◽

Bond Cleavage ◽

Its Sequence ◽

Hydroxybenzoic Acid ◽

X Ray

The enzyme 2,4′-dihydroxyacetophenone dioxygenase (or DAD) catalyses the conversion of 2,4′-dihydroxyacetophenone to 4-hydroxybenzoic acid and formic acid with the incorporation of molecular oxygen. Whilst the vast majority of dioxygenases cleave within the aromatic ring of the substrate, DAD is very unusual in that it is involved in C—C bond cleavage in a substituent of the aromatic ring. There is evidence that the enzyme is a homotetramer of 20.3 kDa subunits each containing nonhaem iron and its sequence suggests that it belongs to the cupin family of dioxygenases. By the use of limited chymotrypsinolysis, the DAD enzyme fromAlcaligenessp. 4HAP has been crystallized in a form that diffracts synchrotron radiation to a resolution of 2.2 Å.

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Static Atomic Displacements in Crystalline Solid Solution Alloys

MRS Proceedings ◽

10.1557/proc-437-181 ◽

1996 ◽

Vol 437 ◽

Cited By ~ 3

Author(s):

Gene Ice ◽

Cullie Sparks ◽

J. Lee Robertson ◽

J. Ernest Epperson ◽

Xiaogang Jiang

Keyword(s):

Synchrotron Radiation ◽

Crystalline Solid ◽

Local Order ◽

Chemical Order ◽

X Ray ◽

Atomic Displacements ◽

X Ray Scattering ◽

New Information ◽

Z Contrast

AbstractAtom size differences induce static displacements from an average alloy lattice and play an important role in controlling alloy phase stability and properties. The details of this role however, are difficult to study; chemical order and displacements are strongly interrelated and static displacements are hard to measure. Diffuse x-ray scattering measurements with tunable-synchrotron radiation can now measure element-specific static displacements with an accuracy of ± 0.1 pm and can simultaneously measure local chemical order out to 20 shells or more. Ideal alloys for diffuse scattering analysis with synchrotron radiation, are those that have previously been the most intractable: alloys with small Z contrast, alloys with only local order and alloys with small size differences. The combination of precise characterization of local chemical order and precise measurement of static displacement provides new information that challenges existing alloy models. We report on an ongoing systematic study of static displacements in the Fe/Ni/Cr alloys and compare the observed static displacements to the static displacements predicted by current theories. The availability of more brilliant 3rd generation hard x-ray sources will greatly enhance these measurements.

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