scholarly journals Distribution of Oxygen at the Ni81Fe19/Ta Interface

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
T. J. A. Mori ◽  
R. D. D. Pace ◽  
W. H. Flores ◽  
M. Carara ◽  
L. F. Schelp ◽  
...  
Keyword(s):  
Fine Structure ◽  
Magnetron Sputtering ◽  
X Ray Diffraction ◽  
Metal Interface ◽  
Edge Structure ◽  
X Ray ◽  
Glass Substrates ◽  
Magnetic Metal ◽  
X Ray Absorption ◽  
Oxygen Atoms

The knowledge of how oxygen atoms are distributed at a magnetic-metal/oxide, or magnetic-metal/non-magnetic-metal interface, can be a useful tool to optimize device production. Multilayered Ni81Fe19/Ta samples consisting of 15 bilayers of 2.5 nm each, grown onto glass substrates by magnetron sputtering from Ni81Fe19 and Ta targets, have been investigated. X-ray absorption near edge structure, extended X-ray absorption fine structure, small angle X-ray diffraction, and simulations were used to characterize the samples. Oxygen atoms incorporated onto Ni81Fe19 films during O2 exposition are mainly bonded to Fe atoms. This partial oxidation of the Ni81Fe19 surface works as a barrier to arriving Ta atoms, preventing intermixing at the Ni81Fe19/Ta interface. The reduction of the Ni81Fe19 surface by the formation of TaOx is observed.

scholarly journals The nature and effects of rhodium and antimony dopants on the electronic structure of TiO2: towards design of Z-scheme photocatalysts

2016 ◽  
Vol 4 (18) ◽  
pp. 6946-6954 ◽  
Author(s):  
E. N. K. Glover ◽  
S. G. Ellington ◽  
G. Sankar ◽  
R. G. Palgrave
Keyword(s):  
Fine Structure ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance ◽  
Diffuse Reflectance Spectroscopy ◽  
Reflectance Spectroscopy ◽  
X Ray Diffraction ◽  
Edge Structure ◽  
X Ray ◽  
Antimony Doping ◽  
X Ray Absorption

The nature and effects of rhodium and antimony doping in TiO2 have been investigated using X-ray diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), Extended X-ray Absorption Fine Structure (EXAFS), X-ray Absorption Near Edge Structure (XANES) and diffuse reflectance spectroscopy.

XAS STUDY OF (BaCuO2)2/(CaCuO2)n SUPERLATTICES

2000 ◽  
Vol 14 (25n27) ◽  
pp. 2628-2633
Author(s):  
S. COLONNA ◽  
F. ARCIPRETE ◽  
A. BALZAROTTI ◽  
G. BALESTRINO ◽  
P. G. MEDAGLIA ◽  
...  
Keyword(s):  
Fine Structure ◽  
Oxygen Vacancies ◽  
Fluorescence Yield ◽  
Octahedral Coordination ◽  
Apical Oxygen ◽  
Edge Structure ◽  
X Ray ◽  
Local Bonding ◽  
X Ray Absorption ◽  
Oxygen Atoms

EXAFS (Extended X-ray Absorption Fine Structure) and XANES (X-Ray Absorption Near Edge Structure) spectroscopies have been used to probe the local bonding of the artificially layered superconducting (BaCuO2)2/(CaCuO2)n (n = 2, 3, 4) superlattices. Fluorescence-yield measurements have been performed above the Cu and Ba K-edges. This study shows that the charge reservoir (CR) block of the Ba/Ca superlattice contains oxygen vacancies randomly distributed in the CuO2 planes and that the two apical oxygen atoms are displaced out of the Ba plane giving rise to buckled BaO planes. These oxygen atoms have a distorted pyramidal and octahedral coordination around Cu at Ba/Ca interface and in the (BaCuO2) block, respectively.

scholarly journals Reactive Dual Magnetron Sputtering: A Fast Method for Preparing Stoichiometric Microcrystalline ZnWO4 Thin Films

Surfaces ◽  
2021 ◽  
Vol 4 (2) ◽  
pp. 106-114
Author(s):  
Yannick Hermans ◽  
Faraz Mehmood ◽  
Kerstin Lakus-Wollny ◽  
Jan P. Hofmann ◽  
Thomas Mayer ◽  
...  
Keyword(s):  
Thin Films ◽  
Magnetron Sputtering ◽  
Photoelectron Spectroscopy ◽  
Fast Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Glass Substrates ◽  
Post Annealing ◽  
Rf Signal ◽  
First Time

Thin films of ZnWO4, a promising photocatalytic and scintillator material, were deposited for the first time using a reactive dual magnetron sputtering procedure. A ZnO target was operated using an RF signal, and a W target was operated using a DC signal. The power on the ZnO target was changed so that it would match the sputtering rate of the W target operated at 25 W. The effects of the process parameters were characterized using optical spectroscopy, X-ray diffraction, and scanning electron microscopy, including energy dispersive X-ray spectroscopy as well as X-ray photoelectron spectroscopy. It was found that stoichiometric microcrystalline ZnWO4 thin films could be obtained, by operating the ZnO target during the sputtering procedure at a power of 55 W and by post-annealing the resulting thin films for at least 10 h at 600 °C. As FTO coated glass substrates were used, annealing led as well to the incorporation of Na, resulting in n+ doped ZnWO4 thin films.

Extended X-ray absorption fine structure and multiple-scattering simulation of nickel dithiolene complexes Ni[S2C2(CF3)2]2n(n= −2, −1, 0) and an olefin adduct Ni[S2C2(CF3)2]2(1-hexene)

2015 ◽  
Vol 22 (1) ◽  
pp. 124-129 ◽  
Author(s):  
Weiwei Gu ◽  
Hongxin Wang ◽  
Kun Wang
Keyword(s):  
Fine Structure ◽  
Multiple Scattering ◽  
Edge Structure ◽  
X Ray ◽  
Absorption Fine ◽  
Square Planar ◽  
Square Planar Complexes ◽  
Uv Visible ◽  
Edge Features ◽  
X Ray Absorption

A series of Ni dithiolene complexes Ni[S2C2(CF3)]2n(n= −2, −1, 0) (1,2,3) and a 1-hexene adduct Ni[S2C2(CF3)2]2(C6H12) (4) have been examined by NiK-edge X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine-structure (EXAFS) spectroscopies. Ni XANES for1–3reveals clear pre-edge features and approximately +0.7 eV shift in the NiK-edge position for `one-electron' oxidation. EXAFS simulation shows that the Ni—S bond distances for1,2and3(2.11–2.16 Å) are within the typical values for square planar complexes and decrease by ∼0.022 Å for each `one-electron' oxidation. The changes in NiK-edge energy positions and Ni—S distances are consistent with the `non-innocent' character of the dithiolene ligand. The Ni—C interactions at ∼3.0 Å are analyzed and the multiple-scattering parameters are also determined, leading to a better simulation for the overall EXAFS spectra. The 1-hexene adduct4presents no pre-edge feature, and its NiK-edge position shifts by −0.8 eV in comparison with its starting dithiolene complex3. Consistently, EXAFS also showed that the Ni—S distances in4elongate by ∼0.046 Å in comparison with3. The evidence confirms that the neutral complex is `reduced' upon addition of olefin, presumably by olefin donating the π-electron density to the LUMO of3as suggested by UV/visible spectroscopy in the literature.

Material Characteristics and Electrical Modeling of Ultra Thin Copper Oxides in ULSI Application

2007 ◽  
Vol 561-565 ◽  
pp. 1225-1228
Author(s):  
Takayuki Ohba
Keyword(s):  
Diffraction Pattern ◽  
Barrier Height ◽  
Oxide Thickness ◽  
Amorphous Structure ◽  
Emission Model ◽  
X Ray Diffraction ◽  
Edge Structure ◽  
X Ray ◽  
Current Emission ◽  
X Ray Absorption

With the highest brilliance synchrotron radiation X-ray (SPring-8) and TEM observations, Cu oxides ranged 2-nm to 10-nm in thickness formed on sputtered Cu has been evaluated. For the plasma-assisted Cu oxide, weak Cu2O and/or CuO X-ray diffraction pattern is observed, while no diffraction pattern in native and thermally (170°C) grown oxides. Those native and thermal oxides show Cu2O coordination observed by XANES (X-ray Absorption Near Edge Structure) method. This suggests that Cu oxide formed at low temperatures consists of stoichiometric Cu2O in an amorphous structure. According to the Fowler-Nordheim (F-N) current emission model, the current emission taking place at Cu2O decreases with increasing of the oxide thickness and its mean barrier height (φB) in the MIM band structure. In case of current density at 106A/cm2 of 1V, it is estimated that the allowable thickness of Cu oxides is approximately 1.5-nm at 1 eV of barrier height.

Fluorescence Extended X-Ray Absorption Fine Structure Study on Local Structures of Rare-Earth-Doped InGaGdN

2016 ◽  
Vol 1133 ◽  
pp. 429-433
Author(s):  
Siti Nooraya Mohd Tawil ◽  
Shuichi Emura ◽  
Daivasigamani Krishnamurthy ◽  
Hajime Asahi
Keyword(s):  
Fine Structure ◽  
Rare Earth ◽  
Nearest Neighbor ◽  
Structure Study ◽  
Edge Structure ◽  
X Ray ◽  
Local Structures ◽  
Absorption Fine ◽  
X Ray Absorption

Local structures around gadolinium atoms in rare-earth (RE)-doped InGaGdN thin films were studied by means of fluorescence extended X-ray absorption fine structure (EXAFS) measured at the Gd LIII-edges. The samples were doped with Gd in-situ during growth by plasma-assisted molecular beam epitaxy (PAMBE). Gd LIII-edge EXAFS signal from the GaGdN, GdN and Gd foil were also measured as reference. The X-ray absorption near edge structure (XANES) spectra around Gd LIII absorption edge of InGaGdN samples observed at room temperature indicated the enhancement of intensities with the increase of Gd composition. Further EXAFS analysis inferred that the Gd atoms in InGaN were surrounded by similar atomic shells as in the case of GaGdN with the evidence indicating majority of Gd atoms substituted into Ga sites of InGaGdN. A slight elongation of bond length for the 2nd nearest-neighbor (Gd–Ga) of sample with higher Gd concentration was also observed.

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