Magnetic Circular Dichroism in X-Ray Fluorescence

1993 ◽  
Vol 307 ◽  
Author(s):  
L.-C. Duda ◽  
C. F. Hague ◽  
D. C. Mancini ◽  
J.-M. Mariot ◽  
C. Marliere ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Theoretical Prediction ◽  
Spin Polarization ◽  
Emission Band ◽  
Fluorescence Spectra ◽  
Magnetic Circular Dichroism ◽  
High Flux ◽  
Circularly Polarized ◽  
X Ray ◽  
Valence Electrons

ABSTRACTX-ray fluorescence spectra from magnetized iron excited by circularly polarized synchrotron radiation are reported. The Fe L2.3 emission band gives rise to a distinct dichroic signal in confirmation of a recent theoretical prediction. These preliminary experiments carried out with “white” and only partially circularly-polarized synchrotron radiation nevertheless reveal an asymmetry which reflects the spin polarization of the Fe 3d valence electrons. The usefulness of developing specialized high flux circularly-polarized sources is clearly established.

In Situ Magnetic-Circular-X-Ray-Dichroism Measurements: An Epitaxial Fe Wedge on Cu(100)

MRS Bulletin ◽  
1999 ◽  
Vol 24 (1) ◽  
pp. 41-45 ◽  
Author(s):  
M.E. Dávila ◽  
D. Arvanitis ◽  
J. Hunter Dunn ◽  
N. Mårtensson ◽  
P. Srivastava ◽  
...  
Keyword(s):  
Ultrathin Films ◽  
Magnetic Circular Dichroism ◽  
Polarized Light ◽  
Measured Quantity ◽  
Easy Magnetization ◽  
Magnetization Direction ◽  
Core Electron ◽  
Circularly Polarized ◽  
X Ray

Circularly polarized x-ray radiation is attracting increasing interest as a tool for the characterization of the electronic, magnetic, and chiral properties of low-dimensional structures. Using circular light (with electric field vector parallel to the orbital plane), a dependence of the measured quantity by changing either the orientation of the light polarization or the magnetization is indicative of the existence of magnetic circular dichroism. It can be observed in x-ray absorption spectroscopy (XAS), in which the photon energy is scanned through an absorption threshold exciting a core electron into an unoccupied valence state using circularly polarized light. Synchrotron radiation sources have made this technique possible. It can also be observed in photo-emission spectroscopy from core and valence levels. Here we focus on magnetic circular x-ray dichroism (MCXD) in XAS as an element-specific tool to investigate magnetic properties of ultrathin films in situ. The application of magneto-optical sum rules enables the determination of the orbital and spin magnetic moments per atom from XAS spectra, as well as the easy magnetization direction.MCXD-based magnetometry in XAS is extensively used by measuring the L absorption edges of 3d-transition metals, where large intensity changes (up to 60%) of the L-edge white lines are observed upon reversal of either the sample magnetization or the light helicity. The high magnetic contrast obtained, combined with the elemental specificity of the technique, allows for the study of very dilute samples such as ultrathin films. We first concentrate on the selection rules governing MCXD in XAS.

Mn Lα,β and F Kα resonant X-ray fluorescence spectroscopy of MnF2

1998 ◽  
Vol 5 (3) ◽  
pp. 1067-1068
Author(s):  
Jun Kawai ◽  
Tokujiro Yamamoto ◽  
Yoshihisa Harada ◽  
Shik Shin
Keyword(s):  
Synchrotron Radiation ◽  
Fluorescence Spectroscopy ◽  
Fluorescence Spectra ◽  
Resonance Fluorescence ◽  
X Ray ◽  
Threshold Energies

Mn Lα,β and F Kα1,2 (K–L 3,2) X-ray fluorescence spectra of MnF2 were measured when the excitation X-ray energy was higher and lower than the threshold energies. Monochromated synchrotron radiation was used for primary excitation. The resonance fluorescence of Mn Lβ and the multiply ionized F Kα3,4 satellites (KL–L 2) were observed.

New nonradioactive microspheres and more sensitive X-ray fluorescence to measure regional blood flow

1992 ◽  
Vol 263 (6) ◽  
pp. H1946-H1957 ◽  
Author(s):  
H. Mori ◽  
S. Haruyama ◽  
Y. Shinozaki ◽  
H. Okino ◽  
A. Iida ◽  
...  
Keyword(s):  
Blood Flow ◽  
Synchrotron Radiation ◽  
Flow Measurement ◽  
Fluorescence Spectra ◽  
Regional Blood Flow ◽  
Energy Dispersive Spectrometer ◽  
X Ray ◽  
Dispersive System ◽  
Monochromatic Synchrotron ◽  
Higher Sensitivity

We developed new nonradioactive microspheres and used more sensitive X-ray fluorescence spectrometers than used previously to measure regional blood flow in the heart and other organs. We demonstrated the chemical stability of eight kinds of heavy element-loaded microspheres and validated their use for regional blood flow measurement by comparing duplicate flows measured with radioactive and/or nonradioactive microspheres in both acute and chronic dog experiments. The wavelength-dispersive spectrometer (Philips PW 1480) has a higher sensitivity than the previously described X-ray fluorescent system and reduced the number of microspheres required for accurate measurement. The fine energy resolution of this system makes it possible to increase the numbers of different kinds of microspheres to be quantitated, but at present only eight kinds are available. We also used a synchrotron radiation-excited energy dispersive spectrometer. The monochromatic synchrotron radiation allowed us to obtain much higher signal-to-background ratios of X-ray fluorescence spectra than with the wavelength-dispersive system (50 dB more for Zr-loaded microspheres) and will enable analysis of fluorescent activity in smaller regions (< 20 mg) than the radioactive method does.

Bright Circularly Polarized Soft X-ray Harmonics for Static and Dynamic X-ray Magnetic Circular Dichroism

2016 ◽  
Author(s):  
Tingting Fan ◽  
Patrick Grychtol ◽  
Ronny Knut ◽  
Carlos Hernández-García ◽  
Daniel D. Hickstein ◽  
...  
Keyword(s):  
Circular Dichroism ◽  
Magnetic Circular Dichroism ◽  
Circularly Polarized ◽  
X Ray ◽  
Circular Dichroïsm
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