Characterization of Local Crystal and Electronic Structure on Sr2CuO2F2+x Material by Synchrotron Radiation

In order to study the evolution of local crystal and electronic structure of Sr2CuO2F2+x, the synchrotron radiation x-ray absorption (XAS) and x-ray absorption fine structure (XAFS) techniques were both performed on different amount of Sr2CuO2F2+x materials. The relationship between high Tc superconductivity and valence state of cooper was mainly discussed. And the effect of by-reproduce SrF2 in non-superconductive Sr2CuO2F2+x on physical property of this material was considered. The experimental results showed that the valence state of Cu and the amount of SrF2 was mainly related with high Tc superconductivity of Sr2CuO2F2+x material, indicating a good method for improving Tc.

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Experimental verification of the need for either jj or intermediate coupling in the 5f states of plutonium

MRS Proceedings ◽

10.1557/proc-802-dd2.6 ◽

2003 ◽

Vol 802 ◽

Author(s):

K. T. Moore ◽

M. A. Wall ◽

A. J. Schwartz ◽

B. W. Chung ◽

J. G. Tobin ◽

...

Keyword(s):

Electronic Structure ◽

Electron Microscope ◽

Synchrotron Radiation ◽

Single Phase ◽

High Spatial Resolution ◽

Intermediate Coupling ◽

X Ray ◽

Transmission Electron ◽

Electron Energy Loss ◽

X Ray Absorption

ABSTRACTHere, we demonstrate the power of electron energy-loss spectroscopy (EELS) in a transmission electron microscope (TEM) to investigate the electronic structure plutonium. Using EELS, TEM, and synchrotron-radiation-based X-ray absorption spectroscopy (XAS), we provide the first experimental evidence that Russell-Saunders (LS) coupling fails for the 5f states of Pu. These results support the assumption that only the use of jj or intermediate coupling is appropriate for the 5f states of Pu. EELS experiments were performed in a TEM and are coupled with image and diffraction data, therefore, the measurements are completely phase specific. It is shown that EELS in a TEM may be used to circumvent the difficulty of producing single-phase or single-crystal samples due to its high spatial resolution.

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Using the Emission of Muonic X-rays as a Spectroscopic Tool for the Investigation of the Local Chemistry of Elements

Nanomaterials ◽

10.3390/nano10071260 ◽

2020 ◽

Vol 10 (7) ◽

pp. 1260

Author(s):

Matteo Aramini ◽

Chiara Milanese ◽

Adrian D. Hillier ◽

Alessandro Girella ◽

Christian Horstmann ◽

...

Keyword(s):

Electronic Structure ◽

Qualitative Method ◽

Hydrogen Desorption ◽

Systematic Investigation ◽

Muonic Atom ◽

X Rays ◽

X Ray ◽

Spectroscopic Tool ◽

X Ray Absorption

There are several techniques providing quantitative elemental analysis, but very few capable of identifying both the concentration and chemical state of elements. This study presents a systematic investigation of the properties of the X-rays emitted after the atomic capture of negatively charged muons. The probability rates of the muonic transitions possess sensitivity to the electronic structure of materials, thus making the muonic X-ray Emission Spectroscopy complementary to the X-ray Absorption and Emission techniques for the study of the chemistry of elements, and able of unparalleled analysis in case of elements bearing low atomic numbers. This qualitative method is applied to the characterization of light elements-based, energy-relevant materials involved in the reaction of hydrogen desorption from the reactive hydride composite Ca(BH4)2-Mg2NiH4. The origin of the influence of the band-structure on the muonic atom is discussed and the observed effects are attributed to the contribution of the electronic structure to the screening and to the momentum distribution in the muon cascade.

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3C-, 4H- and 6H-SiC Bulks Studied by Silicon K-Edge X-Ray Absorption

Materials Science Forum ◽

10.4028/www.scientific.net/msf.740-742.573 ◽

2013 ◽

Vol 740-742 ◽

pp. 573-576 ◽

Cited By ~ 1

Author(s):

Wei Zeng ◽

Zhe Chuan Feng ◽

Rui Sheng Zheng ◽

Ling Yun Jang ◽

Chee Wei Liu

Keyword(s):

Electronic Structure ◽

Fine Structure ◽

High Resolution ◽

Synchrotron Radiation ◽

Angular Dependence ◽

Comparative Studies ◽

X Ray ◽

Absorption Fine ◽

X Ray Absorption

High-resolution synchrotron radiation X-ray absorption of Si K-edge have been employed to investigate 6H-, 4H- and 3C-SiC. Detailed analyses of the extended x-ray absorption fine structure are taken by using the IFEFFIT program, and significant results on the atomic bonding are obtained from these comparative studies. The x-ray absorption near-edge structures of the Si K-edge are investigated, and the electronic structure of 3C-, 4H- and 6H-SiC are studied. In order to investigate the angular dependence, the x-ray absorption near-edge spectra were operated at 55o and 90o of the angle between the surface and the X-ray direction.

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