X-RAY ABSORPTION STUDY OF Mg1-xAlxB2 AT B K-EDGE

2002 ◽  
Vol 16 (11n12) ◽  
pp. 1619-1626 ◽  
Author(s):  
K.-D. TSUEI ◽  
H.-J. LIN ◽  
L.-C. LIN ◽  
T.-Y. HOU ◽  
H.-H. HSIEH ◽  
...  
Keyword(s):  
Room Temperature ◽  
Structural Phase ◽  
Fluorescence Yield ◽  
Absorption Study ◽  
Hole Filling ◽  
Al Doping ◽  
X Ray ◽  
Peak Intensity ◽  
Total Fluorescence ◽  
X Ray Absorption

We have measured B K-edge X-ray absorption spectra of Mg 1-x Al x B 2 (x=0.0 ~ 0.4) using bulk-sensitive total fluorescence yield (TFY) at room temperature and 30 K. In contrast to previous reports no peaks near 192 eV and 194 eV could be observed after repeated scraping, indicating their origin being due to surface contamination. These clean spectra show a peak right above the absorption threshold, anticipated from transition to the unoccupied B 2p states. Except in the intermediate Al doping range of x ~ 0.1 to 0.28 the threshold peak intensity decreases, consistent with pσ-hole filling. The increase of peak intensity in the intermediate range is correlated with structural phase transition.

scholarly journals A zone-plate-based two-color spectrometer for indirect X-ray absorption spectroscopy

2019 ◽  
Vol 26 (4) ◽  
pp. 1266-1271 ◽  
Author(s):  
Florian Döring ◽  
Marcel Risch ◽  
Benedikt Rösner ◽  
Martin Beye ◽  
Philipp Busse ◽  
...  
Keyword(s):  
Absorption Spectroscopy ◽  
Fresnel Zone ◽  
Decay Channel ◽  
Chemical Properties ◽  
Fluorescence Yield ◽  
Complex Materials ◽  
X Ray ◽  
Total Fluorescence ◽  
X Ray Absorption

X-ray absorption spectroscopy (XAS) is a powerful element-specific technique that allows the study of structural and chemical properties of matter. Often an indirect method is used to access the X-ray absorption (XA). This work demonstrates a new XAS implementation that is based on off-axis transmission Fresnel zone plates to obtain the XA spectrum of La0.6Sr0.4MnO3 by analysis of three emission lines simultaneously at the detector, namely the O 2p–1s, Mn 3s–2p and Mn 3d–2p transitions. This scheme allows the simultaneous measurement of an integrated total fluorescence yield and the partial fluorescence yields (PFY) of the Mn 3s–2p and Mn 3d–2p transitions when scanning the Mn L-edge. In addition to this, the reduction in O fluorescence provides another measure for absorption often referred to as the inverse partial fluorescence yield (IPFY). Among these different methods to measure XA, the Mn 3s PFY and IPFY deviate the least from the true XA spectra due to the negligible influence of selection rules on the decay channel. Other advantages of this new scheme are the potential to strongly increase the efficiency and throughput compared with similar measurements using conventional gratings and to increase the signal-to-noise of the XA spectra as compared with a photodiode. The ability to record undistorted bulk XA spectra at high flux is crucial for future in situ spectroscopy experiments on complex materials.

On the origin of dips in total fluorescence yield X-ray absorption spectra: Partial and inverse partial fluorescence yield at the L-edge of cobalt aqueous solution

2012 ◽  
Vol 546 ◽  
pp. 164-167 ◽  
Author(s):  
Mikhail A. Soldatov ◽  
Kathrin M. Lange ◽  
Malte D. Gotz ◽  
Nicholas Engel ◽  
Ronny Golnak ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Absorption Spectra ◽  
Fluorescence Yield ◽  
X Ray ◽  
Total Fluorescence ◽  
X Ray Absorption

X-ray Absorption Study of Electronic Structure in Pristine Bulk Room Temperature Ferromagnetic CeO2

2014 ◽  
Vol 2 (1) ◽  
pp. 40-45
Author(s):  
Arvind Samariya ◽  
S. C. Sharma ◽  
M. Dhawan ◽  
PramodK. Sharma ◽  
S. Pareek ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Room Temperature ◽  
Absorption Study ◽  
X Ray ◽  
X Ray Absorption

Silicon L2, 3-Edge Xanes Study of Platinum Silicide Thin Films

1996 ◽  
Vol 441 ◽  
Author(s):  
S. J. Naftel ◽  
T. K. Sham ◽  
S. R. Das ◽  
D.-X. Xu
Keyword(s):  
Fluorescence Yield ◽  
Detection Methods ◽  
Sampling Depth ◽  
Total Electron ◽  
Edge Structure ◽  
X Ray ◽  
Platinum Silicide ◽  
Depth Difference ◽  
Total Fluorescence ◽  
X Ray Absorption

AbstractPlatinum silicide films, with a typical thickness of several hundred Å, prepared on n-type Si(100) wafers by UHV mnagnetron sputter deposition followed by rapid thermal annealing, have been studied by Si L2,3-edge X-ray absorption near edge structure (XANES) using both total electron and total fluorescence yield detection. Samples of various annealing times were studied. XANES provides information on the electronic structure and morphology of the samples. By utilizing the sampling depth difference between the two detection methods, we can clearly see XANES data from each layer (eg. surface oxide, silicide) in the sample and can estimate the thickness of the oxide layer.

X-RAY ABSORPTION STUDY OF FREE AND BOUND SULPHUR IN MoS2+x(0 ≤ x ≤ 1)

1987 ◽  
Vol 48 (C9) ◽  
pp. C9-1049-C9-1052
Author(s):  
P. BELOUGNE ◽  
B. DEROIDE ◽  
J. M. ESTEVA ◽  
R. C. KARNATAK ◽  
J. V. ZANCHETTA
Keyword(s):  
Absorption Study ◽  
X Ray ◽  
X Ray Absorption

X-ray absorption study of Cu, Zn SOD under high pressure

2000 ◽  
Vol 19 (1-6) ◽  
pp. 277-283 ◽  
Author(s):  
Isabella Ascone ◽  
Andrea Cognigni ◽  
Yann Le Godec ◽  
Jean Paul Itié
Keyword(s):  
High Pressure ◽  
Absorption Study ◽  
X Ray ◽  
X Ray Absorption

Temperature-induced structural phase transitions in RERhSn (RE = Y, Gd-Tm, Lu)

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Simon Engelbert ◽  
Rolf-Dieter Hoffmann ◽  
Jutta Kösters ◽  
Steffen Klenner ◽  
Rainer Pöttgen
Keyword(s):  
Rare Earth ◽  
Phase Transitions ◽  
Driving Force ◽  
Room Temperature ◽  
Structural Phase ◽  
Structural Phase Transitions ◽  
Line Broadening ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
X Ray

Abstract The structures of the equiatomic stannides RERhSn with the smaller rare earth elements Y, Gd-Tm and Lu were reinvestigated on the basis of temperature-dependent single crystal X-ray diffraction data. GdRhSn crystallizes with the aristotype ZrNiAl at 293 and 90 K. For RE = Y, Tb, Ho and Er the HP-CeRuSn type (approximant with space group R3m) is already formed at room temperature, while DyRhSn adopts the HP-CeRuSn type below 280 K. TmRhSn and LuRhSn show incommensurate modulated variants with superspace groups P31m(1/3; 1/3; γ) 000 (No. 157.1.23.1) (γ = 3/8 for TmRhSn and γ = 2/5 for LuRhSn). The driving force for superstructure formation (modulation) is a strengthening of Rh–Sn bonding. The modulation is expressed in a 119Sn Mössbauer spectrum of DyRhSn at 78 K through line broadening.

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