scholarly journals Study of Molecular and Ionic Vapor Composition over CeI3by Knudsen Effusion Mass Spectrometry

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
A. M. Dunaev ◽  
V. B. Motalov ◽  
L. S. Kudin ◽  
M. F. Butman ◽  
K. W. Krämer
Keyword(s):  
Mass Spectrometry ◽  
Saturated Vapor ◽  
Ionic Composition ◽  
Electron Work Function ◽  
Negative Ions ◽  
Knudsen Effusion ◽  
Partial Pressures ◽  
Knudsen Effusion Mass Spectrometry ◽  
Enthalpies Of Sublimation ◽  
The Enthalpy Of Formation

The molecular and ionic composition of vapor over cerium triiodide was studied by Knudsen effusion mass spectrometry. In the saturated vapor over CeI3the monomer, dimer, and trimer molecules and the negative ions I−,CeI4-, andCe2I7-were identified in the temperature range of 753–994 K. The partial pressures of CeI3, Ce2I6, and Ce3I9were determined and the enthalpies of sublimation,ΔsH°(298.15 K) in kJ·mol−1, in the form of monomers (298±9), dimers (415±30), and trimers (423±50) were obtained by the second and third laws of thermodynamics. The enthalpy of formation,ΔfH°(298.15 K) in kJ·mol−1, of the CeI3(-371±9), Ce2I6(-924±30), and Ce3I9(-1585±50) molecules and theCeI4-(-857±19) andCe2I7-(-1451±50) ions were calculated. The electron work function,φe=3.3±0.3 eV, for the CeI3crystal was evaluated.

Vaporization and Thermochemical Study of SrCeO3(s) and SrCe0.95Yb0.05O3(s) by Knudsen Effusion Mass Spectrometry

2008 ◽  
Vol 138 ◽  
pp. 319-330
Author(s):  
Miroslav Miller ◽  
Aleksandra Matraszek
Keyword(s):  
Mass Spectrometry ◽  
Phase Field ◽  
Perovskite Phase ◽  
Thermochemical Study ◽  
Gaseous Species ◽  
Knudsen Effusion ◽  
Partial Pressures ◽  
Knudsen Effusion Mass Spectrometry ◽  
The Enthalpy Of Formation ◽  
Energy Of Formation

The vaporization of samples in the SrO-CeO2 system was investigated by the use of Knudsen effusion mass spectrometry in the temperature range of 1494 K – 1988 K. Partial pressures of the gaseous species O2, CeO2, Sr, and SrO were determined over the samples investigated. The partial pressures of the species were used for the evaluation of thermodynamic activities of CeO2 and SrO in the samples at 1800 K. The enthalpy of formation of SrCeO3(s) was obtained as fH°(298 K) = -1644 ± 21 kJ mol-1. The Gibbs energy of formation of SrCeO3(s) from SrO(s) and CeO2(s) resulted as fG°(1800 K) = -12.5 ± 2.8 kJ mol-1 for the phase field {SrCeO3 + ss of SrO in CeO2} and fG°(1800 K) = -13.7 ± 2.1 kJ mol-1 for the phase field {SrCeO3 + SrO}. The influence of the Yb concentration in the perovskite phase SrCe0.95Yb0.05O3 on the CeO2(s) activity was studied as well. The thermodynamic properties obtained in the present study are discussed on the basis of the data available in literature.

scholarly journals The Composition of Saturated Vapor over 1-Butyl-3-methylimidazolium Tetrafluoroborate Ionic Liquid: A Multi-Technique Study of the Vaporization Process

Entropy ◽  
2021 ◽  
Vol 23 (11) ◽  
pp. 1478
Author(s):  
Anatoliy M. Dunaev ◽  
Vladimir B. Motalov ◽  
Lev S. Kudin
Keyword(s):  
Mass Spectrometry ◽  
Saturated Vapor ◽  
Ion Pairs ◽  
Cell Decomposition ◽  
Vapor Composition ◽  
Equilibrium Conditions ◽  
Decomposition Products ◽  
Knudsen Effusion ◽  
Knudsen Effusion Mass Spectrometry ◽  
Vaporization Process

A multi-technique approach based on Knudsen effusion mass spectrometry, gas phase chromatography, mass spectrometry, NMR and IR spectroscopy, thermal analysis, and quantum-chemical calculations was used to study the evaporation of 1-butyl-3-methylimidazolium tetrafluoroborate (BMImBF4). The saturated vapor over BMImBF4 was shown to have a complex composition which consisted of the neutral ion pairs (NIPs) [BMIm+][BF4−], imidazole-2-ylidene C8N2H14BF3, 1-methylimidazole C4N2H6, 1-butene C4H8, hydrogen fluoride HF, and boron trifluoride BF3. The vapor composition strongly depends on the evaporation conditions, shifting from congruent evaporation in the form of NIP under Langmuir conditions (open surface) to primary evaporation in the form of decomposition products under equilibrium conditions (Knudsen cell). Decomposition into imidazole-2-ylidene and HF is preferred. The vapor composition of BMImBF4 is temperature-depended as well: the fraction ratio of [BMIm+][BF4−] NIPs to decomposition products decreased by about a factor of three in the temperature range from 450 K to 510 K.

Vaporization studies on (manganese + tellurium) withx(Te) > 0.5 by Knudsen effusion mass spectrometry

2002 ◽  
Vol 34 (1) ◽  
pp. 103-117 ◽  
Author(s):  
T.S. Lakshmi Narasimhan, ◽  
M. Sai Baba, ◽  
R. Balasubramanian, ◽  
S. Nalini, ◽  
R. Viswanathan
Keyword(s):  
Mass Spectrometry ◽  
Knudsen Effusion ◽  
Knudsen Effusion Mass Spectrometry

Experimental thermodynamic investigation of the liquid Cu-Li-Sn system by Knudsen Effusion Mass Spectrometry

Calphad ◽  
2019 ◽  
Vol 65 ◽  
pp. 132-140
Author(s):  
L. Bencze ◽  
D. Henriques ◽  
V. Motalov ◽  
Á. Kolay Kovács ◽  
T. Markus
Keyword(s):  
Mass Spectrometry ◽  
Thermodynamic Investigation ◽  
Knudsen Effusion ◽  
Knudsen Effusion Mass Spectrometry

Study of thermal stability of CoSb3 skutterudite by Knudsen effusion mass spectrometry

Calphad ◽  
2019 ◽  
Vol 65 ◽  
pp. 1-7 ◽  
Author(s):  
Pavel Brož ◽  
František Zelenka ◽  
Zdeněk Kohoutek ◽  
Jan Vřešťál ◽  
Vít Vykoukal ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Thermal Stability ◽  
Knudsen Effusion ◽  
Knudsen Effusion Mass Spectrometry ◽  
Thermal Stability Of
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