X-ray line from the dark transition electric dipole

Resonant magnetic Bragg scattering (RMBS) for several reflections has been measured at the Fe K-edge in Fe3O4. The normal and magnetic X-ray absorption near-edge structure (XANES) for two types of Fe ion site (tetrahedral and octahedral) were successfully determined from the analysis of DAFS and RMBS spectra on the assumption that there was an electric dipole transition. The obtained normal XANES for the octahedral site is well explained as a mixture of Fe2+ and Fe3+ ions, and the characteristic feature of the magnetic XANES at the pre-edge peak is mainly contributed from the Fe3+ ion at the tetrahedral site.

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X-ray Natural Circular Dichroism

Acta Crystallographica Section A Foundations and Advances ◽

10.1107/s2053273314084812 ◽

2014 ◽

Vol 70 (a1) ◽

pp. C1518-C1518

Author(s):

Andrei Rogalev ◽

Alexei Bosak ◽

Fabrice Wilhelm ◽

Jose Goulon

Keyword(s):

Circular Dichroism ◽

Absolute Configuration ◽

Electric Dipole ◽

Electric Quadrupole ◽

Interference Term ◽

Opposite Parity ◽

X Ray ◽

Determination Of Absolute Configuration ◽

Circular Dichroïsm

Natural Circular Dichroism was only recently discovered in the x-ray range[1]. This effect stems from the interference terms which mix multipole transition moments of opposite parity: the Electric Dipole-Electric Quadrupole (E1.E2) and the Electric Dipole-Magnetic Dipole (E1.M1) exist only in structures with broken space inversion symmetry. The scalar E1.M1 term known to be responsible for Circular Dichroism at optical wavelengths is usually considered to be vanishingly small for core level spectroscopies. The E1.E2 interference term, on the contrary, can be large in the X-ray region, but it is a parity odd second rank tensor and therefore observable only in 13 non-centrosymmetric crystal classes. X-ray Natural Circular Dichroism has now been detected in the XANES region for several uniaxial and biaxial crystals. It can give access to the absolute configuration of chiral absorbing centers. On the other hand, Chiral-EXAFS, i.e. the analog of Magnetic-EXAFS for Natural Circular Dichroism has also been measured recently using a uniaxial optically active crystal of paratellurite (TeO2). Chiral-EXAFS originates from symmetry allowed multiple scattering paths. In this presentation, we wish to report on recent advances in X-ray natural circular dichroism and its applications. Determination of absolute configuration is illustrated with measurements of both E1.E2 and E1.M1 terms in chiral alpha-Ni(H2O)6·SO4 single crystals. Manifestation of X-ray optical acitivity in magnetoelectric crystals will be illustrated with various dichroisms measured at the Fe K-edge in multiferroic GaFeO3 crystal. Finally, we will review briefly the perspectives open by our experiments.

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Measurement of f orbital hybridization in rare earths through electric dipole-octupole interference in x-ray absorption spectroscopy

Physical Review Materials ◽

10.1103/physrevmaterials.3.120801 ◽

2019 ◽

Vol 3 (12) ◽

Cited By ~ 2

Author(s):

Amélie Juhin ◽

Stephen P. Collins ◽

Yves Joly ◽

Maria Diaz-Lopez ◽

Kristina Kvashnina ◽

...

Keyword(s):

Absorption Spectroscopy ◽

Rare Earths ◽

Electric Dipole ◽

X Ray ◽

Orbital Hybridization ◽

X Ray Absorption

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Neptunium octupole and hexadecapole motifs in NpO2directly from electric dipole (E1) enhanced x-ray Bragg diffraction

Journal of Physics Condensed Matter ◽

10.1088/0953-8984/15/26/301 ◽

2003 ◽

Vol 15 (26) ◽

pp. 4511-4518 ◽

Cited By ~ 34

Author(s):

S W Lovesey ◽

E Balcar ◽

C Detlefs ◽

G van der Laan ◽

D S Sivia ◽

...

Keyword(s):

Electric Dipole ◽

Bragg Diffraction ◽

X Ray

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Band bending and dipole effect at interface of metal-nanoparticles and TiO2 directly observed by angular-resolved hard X-ray photoemission spectroscopy

Physical Chemistry Chemical Physics ◽

10.1039/c8cp00551f ◽

2018 ◽

Vol 20 (16) ◽

pp. 11342-11346 ◽

Cited By ~ 2

Author(s):

Shunsuke Sato ◽

Keita Kataoka ◽

Ryosuke Jinnouchi ◽

Naoko Takahashi ◽

Keita Sekizawa ◽

...

Keyword(s):

Dipole Moment ◽

Metal Nanoparticles ◽

Electric Dipole Moment ◽

Electric Dipole ◽

Photoemission Spectroscopy ◽

Band Bending ◽

X Ray

Angular-resolved HAXPES elucidated band bending and edge shift are caused by electric dipole moment at interface between metal-nanoparticles and TiO2.

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The Solution-State Conformations of 2,4,6-Tri-t-butyl-benzaldehyde and -thiobenzaldehyde

Zeitschrift für Naturforschung A ◽

10.1515/zna-1985-1114 ◽

1985 ◽

Vol 40 (11) ◽

pp. 1157-1161

Author(s):

Henri Lumbroso ◽

Jacqueline Curé ◽

Renzo Okazaki ◽

Akihiko Ishii ◽

Naoki Inamoto

Keyword(s):

Dipole Moment ◽

Chemical Shift ◽

Electric Dipole ◽

Crystalline Phase ◽

Electron Distribution ◽

Inductive Effect ◽

Benzene Solution ◽

Formyl Group ◽

Rotational Angle ◽

X Ray

Formyl-ring conjugation has been examined in benzaldehyde, 2,4,6-trimethyl- and 2,4,6-tri t- butyl-benzaldehyde, and the ab initio STO-3G π-electron distribution in benzaldehyde has been analysed in terms of the mesomeric and π-inductive effect of the formyl group. The electric dipole moment determined in benzene solution at 30.0 °C, and formyl-carbon n.m.r. chemical shift, recorded in deuterochloroform, of 2,4,6-tri-t-butylbenzaldehyde indicate a nonplanar conformation with a formyl-group rotational angle (ϕ) of about 65°. The dipole moment of 2,4,6-tri- t-butylthiobenzaldehyde, also in benzene solution at 30.0 °C, is consistent with a nearly orthogonal model [ϕ ~ 90°), in agreement with the X-ray structure in the crystalline phase giving ϕ = 89.1 ° .

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