Anomalous spin relaxation in graphene nanostructures on the high temperature annealed surface of hydrogenated diamond nanoparticles

2021 ◽  
Author(s):  
V. L. Joseph Joly ◽  
Kazuyuki Takai ◽  
Manabu Kiguchi ◽  
Naoki Komatsu ◽  
Toshiaki Enoki
Keyword(s):  
High Temperature ◽  
Spin Relaxation ◽  
Annealing Temperature ◽  
Vacuum Annealing ◽  
X Ray ◽  
Magnetic Structures ◽  
Diamond Nanoparticles ◽  
Electronic And Magnetic Structures ◽  
X Ray Absorption ◽  
Graphene Nanostructures

The electronic and magnetic structures of diamond nanoparticles with hydrogenated surface are investigated as a function of annealing temperature under vacuum annealing up to 800-1000 oC. Near edge X-ray absorption...

Diffusivity, Solubility and Speciation of Sulphur in Silicate Melts

2006 ◽  
Vol 46 ◽  
pp. 93-97 ◽  
Author(s):  
J. Stelling ◽  
Harald Behrens ◽  
Joachim Deubener ◽  
Stefan Mangold ◽  
Joerg Goettlicher
Keyword(s):  
High Temperature ◽  
Electron Microprobe ◽  
Industrial Production ◽  
Silicate Melts ◽  
Viscosity Data ◽  
Decomposition Products ◽  
X Ray ◽  
Diffusion Couple Technique ◽  
X Ray Absorption ◽  
Diffusion Profiles

Diffusion and solubility of sulphur have important effects on the degassing of silicate melts. Both properties are closely related to the structural incorporation of sulphur in the melt. Depending on the oxygen fugacity, sulphur can be present as sulphide (S2-), sulphite (S4+) or sulphate (S6+). Sulphates play an important role in the industrial production of glasses especially in the fining process. The decomposition products of sulphate amass in bubbles which ascend and homogenize the melt. Structural incorporation of sulphur in glasses is studied by XANES (X-ray Absorption Near Edge Spectroscopy). Diffusion of sulphur is investigated in simple silicate systems using the diffusion couple technique. First diffusion profiles were measured in sodium trisilicate glasses by electron microprobe. The results indicate that sulphur diffusivity in high temperature melts is close to the Eyring diffusivity calculated from viscosity data.

scholarly journals High temperature emissivity, reflectivity, and x-ray absorption of BiFeO3

2010 ◽  
Vol 108 (8) ◽  
pp. 084114 ◽  
Author(s):  
Néstor E. Massa ◽  
Leire del Campo ◽  
Domingos de Souza Meneses ◽  
Patrick Echegut ◽  
Gilberto F. L. Fabbris ◽  
...  
Keyword(s):  
High Temperature ◽  
X Ray ◽  
X Ray Absorption

Xps Analysis of the Sapphire Surface as a Function of High Temperature Vacuum Annealing

1989 ◽  
Vol 159 ◽  
Author(s):  
E.D. Richmond
Keyword(s):  
High Temperature ◽  
Binding Energy ◽  
Photoelectron Spectroscopy ◽  
Vacuum Annealing ◽  
Xps Analysis ◽  
Chemical Changes ◽  
Cleaning Procedure ◽  
Sapphire Surface ◽  
X Ray ◽  
First Time

ABSTRACTFor the first time the (1102) surface of sapphire has been investigated by X-ray photoelectron spectroscopy to ascertain chemical changes resulting from annealing in vacuum at 1300° C and 1450° C. As received substrates had a substantial surface C contaminant. For substrates that were chemically cleaned before inserting them into the MBE system no trace of carbon is detected. A residual flourine contaminant results from the cleaning procedure and is desorbed by the vacuum annealing. Spectra of annealed substrates are compared to the unannealed chemically cleaned substrates. The annealed substrates exhibit 0.4 to 0.5 eV shift to higher binding energy of the Al peak and a 0.3 eV shift to higher binding energy of the O peak. In addition, a 2% depletion of oxygen from the surface occurs.

scholarly journals Study of High-Temperature Behaviour of ZnO by Ab Initio Molecular Dynamics Simulations and X-ray Absorption Spectroscopy

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5206
Author(s):  
Dmitry Bocharov ◽  
Inga Pudza ◽  
Konstantin Klementiev ◽  
Matthias Krack ◽  
Alexei Kuzmin
Keyword(s):  
Molecular Dynamics ◽  
High Temperature ◽  
Ab Initio ◽  
Ab Initio Molecular Dynamics ◽  
Mean Square ◽  
Structural Anisotropy ◽  
X Ray ◽  
Temperature Dependences ◽  
Dynamics Simulations ◽  
X Ray Absorption

Wurtzite-type zinc oxide (w-ZnO) is a widely used material with a pronounced structural anisotropy along the c axis, which affects its lattice dynamics and represents a difficulty for its accurate description using classical models of interatomic interactions. In this study, ab initio molecular dynamics (AIMD) was employed to simulate a bulk w-ZnO phase in the NpT ensemble in the high-temperature range from 300 K to 1200 K. The results of the simulations were validated by comparison with the experimental Zn K-edge extended X-ray absorption fine structure (EXAFS) spectra and known diffraction data. AIMD NpT simulations reproduced well the thermal expansion of the lattice, and the pronounced anharmonicity of Zn–O bonding was observed above 600 K. The values of mean-square relative displacements and mean-square displacements for Zn–O and Zn–Zn atom pairs were obtained as a function of interatomic distance and temperature. They were used to calculate the characteristic Einstein temperatures. The temperature dependences of the O–Zn–O and Zn–O–Zn bond angle distributions were also determined.

Structural and electronic evolution of the As(OH)3 molecule in high temperature aqueous solutions: An x-ray absorption investigation

2004 ◽  
Vol 121 (18) ◽  
pp. 8973-8982 ◽  
Author(s):  
Denis Testemale ◽  
Jean-Louis Hazemann ◽  
Gleb S. Pokrovski ◽  
Yves Joly ◽  
Jacques Roux ◽  
...  
Keyword(s):  
High Temperature ◽  
Aqueous Solutions ◽  
X Ray ◽  
X Ray Absorption

Redox state of iron in peralkaline rhyolitic glass/melt: X-ray absorption micro-spectroscopy experiments at high temperature

2006 ◽  
Vol 231 (4) ◽  
pp. 350-363 ◽  
Author(s):  
N. Métrich ◽  
J. Susini ◽  
E. Foy ◽  
F. Farges ◽  
D. Massare ◽  
...  
Keyword(s):  
High Temperature ◽  
Redox State ◽  
X Ray ◽  
X Ray Absorption

Effect of vacuum annealing on the properties of one step thermally evaporated Sb2S3 thin films for photovoltaic applications

2021 ◽  
Author(s):  
Emna Gnenna ◽  
Naoufel Khemiri ◽  
Minghua Kong ◽  
Maria Isabel Alonso ◽  
Mounir Kanzari
Keyword(s):  
Thin Films ◽  
Annealing Temperature ◽  
Vacuum Annealing ◽  
Xrd Analysis ◽  
Band Gap Energy ◽  
Chemical Compositions ◽  
Optical Parameters ◽  
X Ray ◽  
Vis Spectroscopy ◽  
One Step

Sb2S3 powder was successfully synthesized by solid state reaction technique using high-purity elemental antimony and sulfur. Sb2S3 thin films were deposited on unheated glass substrates by one step thermal evaporation and annealed under vacuum atmosphere for 2 hours at different temperatures 150, 200 and 250 °C. Different characterization techniques were used to better understand the behavior of the Sb2S3 material. X-ray diffraction (XRD) and Raman spectroscopy confirmed the formation of pure Sb2S3 powder with lattice parameters a = 11.07 Å, b = 11.08 Å and c = 3.81 Å. The effect of vacuum annealing temperature on the properties of the films was studied. XRD analysis revealed that as-deposited and annealed films at 150ºC were amorphous in nature whereas those annealed at T ≥ 200°C were polycrystalline with a preferred orientation along (201) plane. The crystallite size of the polycrystalline films showed a decrease from 75.8 to 62.9 nm with the increase of the annealing temperature from 200 to 250 °C. The Raman analysis showed several peaks corresponding to the stibnite Sb2S3 phase. The surface morphology of the films was examined by atomic force microscopy (AFM). The surface roughness decreases slightly as the transformation from the amorphous to the crystalline phase occurs. The chemical compositions of Sb2S3 films were analyzed by energy dispersive X-ray spectroscopy (EDS), revealing that all films were Sb-rich. The optical parameters were estimated from the transmittance and reflectance spectra recorded by UV-Vis spectroscopy. A reduction in the direct band gap energy from 2.12 to 1.70 eV with the increase of annealing temperature was also found.

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