Studies by X-ray Absorption Spectrometry (XAS) of the Local Order at the Zironium Threshold in an -AL2O3 Layer Developed by Oxidation at High Temperature on an Alloy FeCr22Al5

2019 ◽  
Vol 8 (1) ◽  
pp. 1-4
Author(s):  
M. K. Loudjani
Keyword(s):  
High Temperature ◽  
Absorption Spectrometry ◽  
Local Order ◽  
Al2o3 Layer ◽  
X Ray ◽  
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

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
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