The Effect of Thermal Treatments on the Annealing Behaviour of Oxygen-Vacancy Complexes in Irradiated Carbon-Doped Silicon

2005 ◽  
Vol 108-109 ◽  
pp. 205-210 ◽  
Author(s):  
Charalamos A. Londos ◽  
G.D. Antonaras ◽  
M.S. Potsidi ◽  
Andrzej Misiuk ◽  
Valentin V. Emtsev
Keyword(s):  
Thermal Stability ◽  
Infrared Spectroscopy ◽  
Annealing Temperature ◽  
Fast Neutrons ◽  
Thermal Treatments ◽  
Carbon Doped ◽  
Annealing Behaviour ◽  
Doped Silicon ◽  
Temperature Ramps ◽  
Reaction Channels

Cz-grown, carbon-doped silicon samples were irradiated by fast neutrons. We investigated the annealing behaviour of oxygen-related defects, by infrared spectroscopy. We studied the reaction channels leading to the formation of various VmOn defects and in particular the VOn defects formed by the accumulation of oxygen atoms and vacancies in the initially produced by the irradiation VO defects, as the annealing temperature ramps upwards. We mainly focused on bands appearing in the spectra above 450 oC. A band at 1005 cm-1 is found to be the convolution of two bands at 1004 and 1009 cm-1. The latter band has the same thermal stability with the 983 cm-1 of the VO4 defect and therefore is also attributed to this defect. The former band has the same thermal stability with three other bands at 965, 1034 and 1048 cm-1. These four bands may be attributed to VOn (n=5,6) defects, although other VmOn complexes are also potential candidates. Furthermore, we found that pre-treatments of the samples at 1000 oC, with or without the application of high hydrostatic pressure lead to an increase in the concentration of the VO2, VO3 and generally VOn defects in comparison with that of the untreated samples.

Recovering the performance of irradiated high temperature superconductors for use in fusion magnets

2021 ◽  
Author(s):  
Raphael Unterrainer ◽  
David X Fischer ◽  
Alena Lorenz ◽  
Michael Eisterer
Keyword(s):  
Annealing Temperature ◽  
High Temperature Superconductors ◽  
Life Time ◽  
Neutron Radiation ◽  
Fast Neutrons ◽  
Thermal Treatments ◽  
Superconducting Transition ◽  
Commercial Viability ◽  
Cost Efficient ◽  
Critical Current Density Jc

Abstract The magnets confining the plasma in future fusion devices will be exposed to a significant destructive flux of fast neutrons. Particularly, in cost efficient compact reactor designs, the degradation of the superconductor becomes an issue and directly impacts the commercial viability. We report on the influence of neutron radiation on the superconducting transition temperature, Tc, and the critical current density, jc, and discuss possibilities to counteract the degradation by thermal treatments. We found that the degradation in Tc and jc are closely related to each other, likely by the expected loss of superfluid density; thus, Tc is a very useful indicator for the magnets' degradation. It increases linearly with annealing temperature and around 25 % of the decrease can be recovered by annealing at 150 °C and about 60 % at 400 °C, which would more than double the magnet’s life time. However, a loss of oxygen has to be impeded in the latter case.

Infrared Spectroscopy Characterization of Marine Shells

2001 ◽  
Vol 711 ◽  
Author(s):  
Octavio Gomez-Martinez ◽  
Daniel H. Aguilar ◽  
Patricia Quintana ◽  
Juan J. Alvarado-Gil ◽  
Dalila Aldana ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Crassostrea Virginica ◽  
Thermal Treatments ◽  
Vibration Modes ◽  
Lattice Vibrations ◽  
Vibration Frequencies ◽  
Mussel Shells ◽  
Carbonate Lattice

ABSTRACTFourier Transform infrared spectroscopy has been employed to study the shells of two kind of mollusks, American oysters (Crassostrea virginica) and mussels (Ischadium recurvum). It is shown that it is possible to distinguish the different calcium carbonate lattice vibrations in each case, mussel shells present aragonite vibration frequencies, and the oyster shells present those corresponding to calcite. The superposition, shift and broadening of the infrared bands are discussed. Changes in the vibration modes due to successive thermal treatments are also reported.

Thermal stability and plasmonic photothermal conversion of surface-modified solar nanofluids: Comparing prolonged and cyclic thermal treatments

2021 ◽  
Vol 244 ◽  
pp. 114463
Author(s):  
Omar Z. Sharaf ◽  
Nahla Rizk ◽  
Catherine J. Munro ◽  
Chakra P. Joshi ◽  
Waqas Waheed ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Thermal Treatments ◽  
Photothermal Conversion ◽  
Surface Modified

scholarly journals Thermal and structural characterization of the vitreous samples in the SiO2 - PbO - Na2O system

2006 ◽  
pp. 89-95 ◽  
Author(s):  
Catalina Mocioiu ◽  
Georgeta Jitianu ◽  
Maria Zaharescu
Keyword(s):  
Thermal Stability ◽  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Infrared Spectroscopy ◽  
Silicate Glasses ◽  
Lead Silicate ◽  
High Chemical ◽  
Nuclear Techniques ◽  
Infrared Data

Lead-containing glasses have been used from the ancient time. Recently, due to the possible application in optics, electronics, nuclear techniques, wastes inactivation. the interest in these types of glasses has been renewed. For lead waste inactivation, glasses with high amount of PbO in the composition are required, those exhibiting at the same time a high chemical and thermal stability. Thermal behavior of lead-silicate glasses was examined by differential thermal analysis (DTA). Infrared spectroscopy was used to investigate the structure of the glasses. The spectra were interpreted in terms of the structures of silicate group by comparison with the spectra of other silicate crystals. The DTA and infrared data were correlated with the chemical stability tests.

scholarly journals Thermal stability and thermal decomposition of sucralose

2018 ◽  
Vol 39 (4) ◽  
pp. 21
Author(s):  
Gilbert Bannach ◽  
Rafael R. Almeida ◽  
Luis G. Lacerda ◽  
Egon Schnitzler ◽  
Massao Ionashiro
Keyword(s):  
Thermal Stability ◽  
Thermal Analysis ◽  
Differential Scanning Calorimetry ◽  
Thermal Decomposition ◽  
Differential Thermal Analysis ◽  
Infrared Spectroscopy ◽  
Scanning Calorimetry ◽  
Thermoanalytical Techniques ◽  
Thermal Stability Of

Several papers have been described on the thermal stability of the sweetener, C12H19Cl3O8 (Sucralose). Nevertheless no study using thermoanalytical techniques was found in the literature. Simultaneous thermogravimetry and differential thermal analysis (TG-DTA), differential scanning calorimetry (DSC) and infrared spectroscopy, have been used to study the thermal stability and thermal decomposition of sweetener.

Sign in / Sign up

Export Citation Format

Share Document