History and Cross-Disciplinary Perspective of Compositional Imaging and Mapping With Nexafs Microscopy

In Near Edge X-ray Absorption Fine Structure (NEXAFS) microscopy, excitations of core electrons into unoccupied molecular orbitals or electronic states provide sensitivity to a wide variety of chemical functionalities in molecules and solids. This sensitivity complements infrared (IR) spectroscopy, although the NEXAFS spectra are not quite as specific and “rich” as IR spectra. The sensitivity of NEXAFS to distinguish chemical bonds and electronic structures covers a wide variety of samples: from metals to inorganics and organics. (There is a tendency in the community to use the term NEXAFS for soft x-ray spectroscopy of organic materials, while for inorganic materials or at higher energies X-ray Absorption Near Edge Spectroscopy (XANES) is utilized, even though the fundamental physics is the same.) The sensitivity of NEXAFS is particularly high to distinguish saturated from unsaturated bonds. NEXAFS can also detect conjugation in a molecule, as well as chemical shifts due to heteroatoms.

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The Control of Electronic States Spreading Outside the Conjugated Polymer Surface

MRS Proceedings ◽

10.1557/proc-0965-s13-02 ◽

2006 ◽

Vol 965 ◽

Author(s):

Xiao Tao Hao ◽

Takuya Hosokai ◽

Noritaka Mitsuo ◽

Satoshi Kera ◽

Kazuyuki Sakamoto ◽

...

Keyword(s):

Thin Films ◽

Photoelectron Spectroscopy ◽

Electronic Structures ◽

Conjugated Polymer ◽

Polymer Surface ◽

Electronic States ◽

Penning Ionization ◽

X Ray ◽

Molecular Ordering ◽

X Ray Absorption

ABSTRACTThe surface electronic structures of conjugated regio regular and regio random poly (3- hexylthiophene) (rr-P3HT and rra-P3HT) thin films were studied by near edge X-ray absorption fine structure spectroscopy, ultraviolet photoelectron spectroscopy and Penning ionization electron spectroscopy (PIES). The distribution of the surface electronic states was controlled on rr-P3HT and rra-P3HT thin films with different molecular ordering by varying the coating process and PIES was adopted to observe the electronic states existing outside the surface.

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Study of MgXZn1-XO Alloys (0

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.663.361 ◽

2013 ◽

Vol 663 ◽

pp. 361-365 ◽

Cited By ~ 3

Author(s):

Wei Zheng ◽

Zhe Chuan Feng ◽

Fan Hsiu Chang ◽

Jyh Fu Lee ◽

Rui Sheng Zheng ◽

...

Keyword(s):

Fine Structure ◽

High Resolution ◽

Detailed Analysis ◽

Absorption Spectroscopy ◽

Electronic Structures ◽

Chemical Bonds ◽

Absorption Data ◽

Edge Structure ◽

X Ray ◽

X Ray Absorption

High-resolution K-edge x-ray absorption data are presented for Mg, Zn and O of Mg1-xZnxO films. A detailed analysis of the extended x-ray absorption fine structure by using the IFEFFIT program is given, and the Zn form chemical bonds with O are obtained. The x-ray absorption near-edge structure of Mg, Zn and O K-edge are investigated, and the electronic structures of Mg1-xZnxO with various compositions are studied.

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Determination of Bond Lengths and Electronic Structure of Cd1-xZnxTe Ternary Alloys by Synchrotron Radiation

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.706-708.56 ◽

2013 ◽

Vol 706-708 ◽

pp. 56-59 ◽

Cited By ~ 2

Author(s):

Wei Zheng ◽

Yu Li Wu ◽

Yen Ting Chen ◽

Zhe Chuan Feng ◽

Jyh Fu Lee ◽

...

Keyword(s):

Electronic Structure ◽

Fine Structure ◽

Synchrotron Radiation ◽

Electronic Structures ◽

Ternary Alloys ◽

Chemical Bonds ◽

Edge Structure ◽

X Ray ◽

X Ray Absorption

High-resolution synchrotron radiation x-ray absorption spectroscopy on Zn K-, Cd L3- and Te L3-edges for Cd1-xZnxTe ternary alloys with x = 0.10, 0.30, 0.50 and 0.90 are presented. A detailed analysis of the extended x-ray absorption fine structure using the IFEFFIT program, and the chemical bonds of Zn-Te are obtained, suggesting distortion of the Te sub-lattice. The x-ray absorption near-edge structure of the Zn K-, Cd L3- and Te L3-edge are investigated, and the electronic structures of Cd1-xZnxTe with various compositions are studied.

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Extended Core Edge Fine Structure in the E.M.

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s1431927600000489 ◽

1980 ◽

Vol 38 ◽

pp. 120-121

Author(s):

R.D. Leapman

Keyword(s):

Fine Structure ◽

Electron Scattering ◽

Inelastic Electron ◽

High Resolution Imaging ◽

X Ray ◽

Analytical Electron ◽

Analytical Electron Microscope ◽

Core Electrons ◽

Resolution Imaging ◽

X Ray Absorption

Extended X-ray Absorption Fine Structure (EXAFS) analysis makes use of synchrotron radiaion to measure modulations in the absorption coefficient above core edges and hence to obtain information about local atomic environments. EXAFS arises when ejected core electrons are backscattered by surrounding atoms and interfere with the outgoing waves. Recently, interest has also been shown in using inelastic electron scattering1-4. Some advantages of Extended X-ray-edge Energy Loss Fine Structure (EXELFS) are: a) small probes formed by the analytical electron microscope give spectra from μm to nm sized areas, compared with mm diameter areas for the X-ray technique, b) EXELFS can be combined with other techniques such as electron diffraction or high resolution imaging, and c) EXELFS is sensitive to low Z elements with K edges from ˜200 eV to ˜ 3000 eV (B to Cl).

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