1212-Molybdo-Cuprates; effect of oxygenation in the structure, properties and electronic states

2014 ◽  
Vol 1655 ◽  
Author(s):  
Sourav Marik ◽  
A. J. Dos santos-Garcia ◽  
Christine Labrugere ◽  
Emilio Morán ◽  
Olivier Toulemonde ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Oxidation Reaction ◽  
Short Range ◽  
Magnetic Measurements ◽  
Electronic States ◽  
The Other ◽  
Superconducting Transition ◽  
X Ray ◽  
Flowing Oxygen ◽  
Structure Properties

ABSTRACTThe influence of oxygenation in the magnetism, superconductivity and electronic states for the Mo0.3Cu0.7Sr2RECu2Oy (RE = Y, Er and Tm) compounds are discussed here. The magnetic measurements on the as-prepared (AP) samples suggest the existence of short-range magnetic correlations due to the presence of the paramagnetic MoV cations in the copper chain site. On the other hand, all the oxygenated samples are not magnetic but superconducting. The high pressure oxygenated sample shows the highest superconducting transition temperature of TC = 84 K. The influence of oxygenation in the electronic states for the Mo0.3Cu0.7Sr2YCu2Oy system associated with an oxidation reaction leading from a non-superconducting to a superconducting state has also been investigated by means of X-ray photoelectron spectroscopy (XPS). XPS measurements show the predominance of the MoV oxidation state over the MoVI one in the AP material; annealing under flowing oxygen enhances both the MoVI and CuII amounts. A detailed study of the electronic states for the Mo0.3Cu0.7Sr2YCu2Oy samples has been performed and is also discussed.

scholarly journals Pore Modification and Phosphorus Doping Effect on Phosphoric Acid-Activated Fe-N-C for Alkaline Oxygen Reduction Reaction

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1519
Author(s):  
Jong Gyeong Kim ◽  
Sunghoon Han ◽  
Chanho Pak
Keyword(s):  
Phosphoric Acid ◽  
Photoelectron Spectroscopy ◽  
Structural Changes ◽  
Electronic States ◽  
Nitrogen Adsorption ◽  
Reduction Reaction ◽  
Phosphorus Doping ◽  
X Ray ◽  
Precious Metal Catalysts ◽  
Adsorption Desorption

The price and scarcity of platinum has driven up the demand for non-precious metal catalysts such as Fe-N-C. In this study, the effects of phosphoric acid (PA) activation and phosphorus doping were investigated using Fe-N-C catalysts prepared using SBA-15 as a sacrificial template. The physical and structural changes caused by the addition of PA were analyzed by nitrogen adsorption/desorption and X-ray diffraction. Analysis of the electronic states of Fe, N, and P were conducted by X-ray photoelectron spectroscopy. The amount and size of micropores varied depending on the PA content, with changes in pore structure observed using 0.066 g of PA. The electronic states of Fe and N did not change significantly after treatment with PA, and P was mainly found in states bonded to oxygen or carbon. When 0.135 g of PA was introduced per 1 g of silica, a catalytic activity which was increased slightly by 10 mV at −3 mA/cm2 was observed. A change in Fe-N-C stability was also observed through the introduction of PA.

Preparation of Graphene/MoS2 Composite for Detection of Dopamine

2022 ◽  
Vol 905 ◽  
pp. 192-197
Author(s):  
Lin Lin Cai ◽  
Xiao Qing Jiang
Keyword(s):  
Raman Spectra ◽  
Photoelectron Spectroscopy ◽  
The Other ◽  
Organic Salt ◽  
Carbon Electrode ◽  
Sodium Tartrate ◽  
X Ray ◽  
Transmission Electron ◽  
Linear Detection ◽  
Potassium Sodium Tartrate

A new composite of graphene/MoS2 is synthesized by co-exfoliation of graphite and MoS2 in isopropanol (IPA) using the organic salt potassium sodium tartrate as the assistant. The composite is characterized by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and Raman spectra. The results of TEM, XPS, and Raman spectra all illustrate that the graphene/MoS2 composite has been synthesized successfully. Furthermore, the composite is modified on glassy carbon electrode to fabricate a sensor to detect dopamine (DA). The sensor shows two linear detection ranges for DA. One is 1-45 μM and the other is 45-120 μΜ. The detection limit of the sensor (S/N=3) is 0.76 μM.

Electronic states of core levels and valence bands for KxC60 studied by X-ray photoelectron spectroscopy

1991 ◽  
Vol 181 (4-6) ◽  
pp. 320-324 ◽  
Author(s):  
Y. Fukuda ◽  
N. Sanada ◽  
M. Nagoshi ◽  
T. Takahashi ◽  
H. Katayama-Yoshida ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Electronic States ◽  
X Ray ◽  
Valence Bands

Magnetic cluster developement in In1−x MnxSb semiconductor alloys

Open Physics ◽  
2010 ◽  
Vol 8 (4) ◽  
Author(s):  
Lidia Rednic ◽  
Iosif Deac ◽  
Eugen Dorolti ◽  
Marin Coldea ◽  
Vasile Rednic ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Magnetic Measurements ◽  
Semiconductor Alloys ◽  
X Ray Diffraction ◽  
Magnetic Cluster ◽  
X Ray ◽  
Small Magnetic Field ◽  
Transmission Electron

AbstractX-ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), Transmission Electron Microscopy (TEM) and magnetic measurements as a function of applied magnetic field and temperature for In1−x MnxSb (0.05≤x≤0.2) system are reported. Magnetic measurements performed at high and small magnetic field in ZFC and FC indicate the coexistence of ferromagnetic In1−x MnxSb solid solution and two types of magnetic cluster: ferromagnetic MnSb and ferrimagnetic Mn2Sb. XPS valence band and Mn 2p core level spectra have confirmed the presence of MnSb and Mn2Sb phases. TEM images show some manganese antimonide phase microinclusions with dimension between (30–40) nm.

In situ study of an oxidation reaction on a Pt/C electrode by ambient pressure hard X-ray photoelectron spectroscopy

2014 ◽  
Vol 105 (13) ◽  
pp. 131602 ◽  
Author(s):  
Yasumasa Takagi ◽  
Heng Wang ◽  
Yohei Uemura ◽  
Eiji Ikenaga ◽  
Oki Sekizawa ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Oxidation Reaction ◽  
Ambient Pressure ◽  
X Ray ◽  
In Situ Study

scholarly journals Interference stabilization of autoionizing states in molecular N2 studied by time- and angular-resolved photoelectron spectroscopy

2016 ◽  
Vol 194 ◽  
pp. 509-524 ◽  
Author(s):  
Martin Eckstein ◽  
Nicola Mayer ◽  
Chung-Hsin Yang ◽  
Giuseppe Sansone ◽  
Marc J. J. Vrakking ◽  
...  
Keyword(s):  
Decay Rate ◽  
Photoelectron Spectroscopy ◽  
Rydberg States ◽  
Electronic States ◽  
The Other ◽  
Photoelectron Spectra ◽  
Angular Distributions ◽  
Velocity Map Imaging ◽  
Imaging Spectrometer ◽  
Exponential Decay Rate

An autoionizing resonance in molecular N2 is excited by an ultrashort XUV pulse and probed by a subsequent weak IR pulse, which ionizes the contributing Rydberg states. Time- and angular-resolved photoelectron spectra recorded with a velocity map imaging spectrometer reveal two electronic contributions with different angular distributions. One of them has an exponential decay rate of 20 ± 5 fs, while the other one is shorter than 10 fs. This observation is interpreted as a manifestation of interference stabilization involving the two overlapping discrete Rydberg states. A formalism of interference stabilization for molecular ionization is developed and applied to describe the autoionizing resonance. The results of calculations suggest, that the effect of the interference stabilization is facilitated by rotationally-induced couplings of electronic states with different symmetry.

Plasma Cleaning and Nitridation of Sapphire Substrates for AlxGa1-xN Epitaxy as Studied by ARXPS and XPD

1997 ◽  
Vol 468 ◽  
Author(s):  
M. Seelmann-Eggebert ◽  
H. Zimmermann ◽  
H. Obloh ◽  
R. Niebuhr ◽  
B. Wachtendorf
Keyword(s):  
High Temperature ◽  
Photoelectron Spectroscopy ◽  
Short Range ◽  
Short Range Order ◽  
Thermal Treatments ◽  
Plasma Cleaning ◽  
Substrate Preparation ◽  
X Ray ◽  
Sapphire Substrates ◽  
Mocvd Reactor

ABSTRACTThe influence of plasma and thermal treatments on the structure and composition of sapphire (00–1) surfaces have been studied by hemispherically recorded x-ray photoelectron spectroscopy in view of substrate preparation for the epitaxy of GaN. Producing well-ordered surfaces, O2 plasma based treatments are found to efficiently remove surface contamination. AlN films with good short-range order are obtained by a simple high temperature nitridation step in the MOCVD reactor.

Photoelectron Angular Distributions Of Ultrathin NI/CU(001) Films

1996 ◽  
Vol 437 ◽  
Author(s):  
G.J. Mankey ◽  
K. Subramanian ◽  
R.L. Stockbauer ◽  
R.L. Kurtz
Keyword(s):  
Photoelectron Spectroscopy ◽  
Periodic Potential ◽  
Electronic States ◽  
Linear Dichroism ◽  
Angular Distributions ◽  
X Ray ◽  
Photoelectron Diffraction ◽  
Ellipsoidal Mirror ◽  
Magnetic Linear Dichroism ◽  
Photoelectron Angular Distributions

AbstractWe present measurements of the evolution with film thickness of the 3d electronic states at the Fermi energy of ultrathin Ni films. The morphology and thickness of the films is determined from x-ray photoelectron spectroscopy. x-ray photoelectron diffraction and x-ray magnetic linear dichroism using synchrotron radiation. Photoelectron angular distributions were measured using an ellipsoidal mirror analyzer. Even at submonolayer Ni coverages, the 3d electronic states exhibit bulk-like properties. This is attributed to the short screening length of electrons in metals, the localization of the 3d electrons, the similarity of the Ni and Cu ion cores, and finally the interaction with the underlying fcc periodic potential.

The Control of Electronic States Spreading Outside the Conjugated Polymer Surface

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.

Near-threshold ultraviolet-laser ablation of Kapton film investigated by x-ray photoelectron spectroscopy

2003 ◽  
Vol 18 (1) ◽  
pp. 53-59 ◽  
Author(s):  
D. W. Zeng ◽  
K. C. Yung ◽  
C. S. Xie
Keyword(s):  
Free Radical ◽  
Photoelectron Spectroscopy ◽  
Oxidation Reaction ◽  
Oxidation Mechanism ◽  
Pulse Number ◽  
Ultraviolet Laser ◽  
Thermally Induced ◽  
X Ray ◽  
Induced Decomposition ◽  
Near Threshold

Near-threshold ultraviolet-laser (355 nm) ablation of 125-μm thick Kapton films was investigated in detail using x-ray photoelectron spectroscopy. Different from the irradiation at higher fluences, the contents of the oxygen, amide group, and C–O group on the ablated surface increased with an increase in the pulse number, whereas the carbon contents decreased, although the contents of the nitrogen and the carbonyl group (C = O) decreased slightly. This implied that there was no carbon-rich residue on the ablated surface. Near the ablation threshold, only photolysis of the C–N bond in the imide rings and the diaryl ether group (C–O) took place due to a low surface temperature rise, and the amide structure and many unstable free radical groups were created. Sequentially, the oxidation reaction occurred to stabilize the free radical groups. The decomposition and oxidation mechanism could explain the intriguing changes of the chemical composition and characteristics of the ablated surface. In addition, the content of the C–O group depended on the opposite factors: the thermally induced decomposition of the ether groups and the pyrolysis of the Caryl–C bond. Upon further irradiation, the cumulative heating may induce the breakage of the Caryl–C bond and enhance the oxidation reaction, resulting in an increase of the content of the C–O group.

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