Isotopic Effect on the Melting Point of Lithium Nitrate

1970 ◽  
Vol 25 (5) ◽  
pp. 697-699 ◽  
Author(s):  
Bert Jansson ◽  
Arnold Lundén
Keyword(s):  
Melting Point ◽  
Isotope Effects ◽  
Zone Melting ◽  
Isotopic Effect ◽  
Lithium Nitrate ◽  
Lithium Metal ◽  
Self Diffusion ◽  
Fee Structure ◽  
The Difference ◽  
Self Diffusion Coefficient

The techniques of segregation during normal freezing and of zone melting have been used to establish that the melting point of 6LiNO3 is higher than that of 7LiNO3. The difference is of the order of 0.03 °C. The isotope shift of the melting point is in the opposite direction of the isotope effects found previously for phase transitions in solid lithium metal and lithium sulfate. For the latter salt a recalculation based on a more accurate value for the self-diffusion coefficient shows that the temperature of transition at about 575 °C to a fee structure is about 0.08 degr. lower for 6Li2SO4 than for 7Li2SO4.

Self-Diffusion in Molten Lithium Nitrate

1992 ◽  
Vol 47 (10) ◽  
pp. 1047-1050 ◽  
Author(s):  
C. Herdlicka ◽  
J. Richter ◽  
M. D. Zeidler
Keyword(s):  
Diffusion Coefficient ◽  
Diffusion Coefficients ◽  
Spin Echo ◽  
The Self ◽  
Lithium Nitrate ◽  
Equimolar Ratio ◽  
Self Diffusion ◽  
Field Gradients ◽  
Molten Lithium ◽  
Self Diffusion Coefficient

AbstractSelf-diffusion coefficients of 7Li+ ions have been measured in molten LiNO3 with several compositions of 6Li+ and 7Li+ over a temperature range from 537 to 615 K. The NMR spin-echo method with pulsed field gradients was applied. It was found that the self-diffusion coefficient depends on the isotopic composition and shows a maximum at equimolar ratio. At temperatures above 600 K this behaviour disappears.

Self-Diffusion of Tl+ in Molten Thalium Nitrate

1977 ◽  
Vol 32 (12) ◽  
pp. 1433-1434
Author(s):  
S. Zuca ◽  
M. Constantinescu
Keyword(s):  
Diffusion Coefficient ◽  
Melting Point ◽  
The Self ◽  
Ionic Interactions ◽  
Temperature Range ◽  
Self Diffusion ◽  
Capillary Method ◽  
Self Diffusion Coefficient

Abstract The self-diffusion coefficient of Tl+ in molten TlNO3 in a temperature range of about 100° above the melting point was measured by the "diffusion-into-the capillary" method. The obtained results are discussed in terms of ionic interactions occuring in TlNO3 melt.

Diffusion of Nb in Nb-H Alloys

2005 ◽  
Vol 237-240 ◽  
pp. 346-351
Author(s):  
Yoshihiro Yamazaki ◽  
Takahiro Iida ◽  
Yoshiaki Iijima ◽  
Yuh Fukai
Keyword(s):  
Diffusion Coefficient ◽  
Activation Energies ◽  
The Self ◽  
Exponential Factor ◽  
Temperature Range ◽  
Self Diffusion ◽  
Diffusion Enhancement ◽  
The Difference ◽  
Self Diffusion Coefficient ◽  
Hydrogen Dissolution

Self-diffusion coefficient of 95Nb in NbHx alloys (x=0.05,0.25 and 0.3) has been determined in the temperature range from 823 to 1323 K by using a serial sputter-microsectioning technique. The self-diffusion coefficient of Nb in the NbHx alloys are larger than that in Nb, suggesting that vacancies are formed by hydrogen dissolution, that is, the formation of hydrogen-induced vacancies. The value of the pre-exponential factor for the Nb diffusion in the NbH0.05 alloy is five times larger than that in Nb, while the difference in the activation energies between the NbH0.05 alloy and pure Nb is small. The self-diffusion enhancement in the NbH0.05 alloy is mainly caused by lowering in vibrational frequencies of atoms in the immediate neighborhood of hydrogen-induced vacancies.

scholarly journals Velocity autocorrelation function and self-diffusion coefficient in large molecular dynamics models of liquid argon and water

2021 ◽  
Vol 13 (2) ◽  
pp. 149-156
Author(s):  
Yuri I. Naberukhin ◽  
◽  
Alexey V. Anikeenko ◽  
Vladimir P. Voloshin ◽  
◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Diffusion Coefficient ◽  
Autocorrelation Function ◽  
Liquid Argon ◽  
Time Interval ◽  
Velocity Autocorrelation Function ◽  
Self Diffusion ◽  
Velocity Autocorrelation ◽  
The Difference ◽  
Self Diffusion Coefficient

Autocorrelation function of the particle velocity Z(t) is calculated using the molecular dynamics method in the models of liquid argon and water. The large size of the models (more than a hundred thousand particles) allowed us to trace these functions up to 50 picoseconds in argon and up to 10 picoseconds in water, and to achieve a calculation accuracy sufficient for analytical analysis of their shape. The difference in the determination of the self-diffusion coefficient using Einstein's law and the integral of Z(t) (Green-Kubo integral) is analyzed and it is shown to be 3% at best when t is of the order of several picoseconds. The asymptote of the function Z(t) in argon is close to the power law αt–3/2 predicted by hydrodynamics, but with an amplitude that depends on the time interval under consideration. In water, the asymptote of Z(t) has nothing in common with that in argon: it has α < 0 and the exponent is close to -5/2, and not to -3/2.

Notizen: Diffusion of Silver in Solid Lithium Metal

1968 ◽  
Vol 23 (3) ◽  
pp. 473-474
Author(s):  
A. Ott ◽  
A. Nordén-Ott
Keyword(s):  
Thin Film ◽  
Activation Energy ◽  
Tracer Diffusion ◽  
Lithium Metal ◽  
Self Diffusion ◽  
Sectioning Method ◽  
Arrhenius Relation ◽  
The Difference

The diffusion of Ag110m in lithium has been measured, using a thin film plating and sectioning method, between 67° and 160 °C. The data fit the Arrhenius relationD=D0·exp(—Q/R T),whereD0=0.37±0.13 cm2 sec-1 and Q=12.83 ±0.25 kcal·mol—1.There are reasons to believe that diffusion takes place by a highly relaxed or cooperative mechanism. The difference in activation energy between Ag tracer diffusion in Li and Li self-diffusion is very small.

Electromigration in Molten and Solid Binary Sulfate Mixtures: Relative Cation Mobilities and Transport Numbers

1966 ◽  
Vol 21 (10) ◽  
pp. 1592-1600 ◽  
Author(s):  
Vladislav Ljubimov ◽  
Arnold Lundén
Keyword(s):  
Melting Point ◽  
Eutectic Composition ◽  
Isotope Effects ◽  
Mass Effect ◽  
Cation Transport ◽  
Relative Difference ◽  
The Other ◽  
Transport Numbers ◽  
Li Ion ◽  
The Difference

The electrolytic displacement of the two cations relative to each other has been studied in solid (Li, Ag)2SO4 (93 eq. % Li) at 700 °C, solid (Li, K)2SO4 (91% Li) at 575 °C and molten (Li, K)2SO4 (41 — 90% Li). For melts containing more than about 52% Li the Li ions have a higher mobility (at about 740 °C) than the K ions, while the latter have the highest mobility in mixtures where K is the more abundant cation. The relative difference (Δb/b) between the mobilities of the two cations exceeds 15% already at concentrations some 8% off from the equimobility concentration. For the eutectic composition, 80% Li, Δb/b was about 60% independent of the temperature (590 — 835 °C). For mixtures containing 90% Li it was established that Δb/b changes its sign at the melting point. Thus, the mobility of the Li ion was of the order of half the mobility of the other ion in the solid systems, while it was about twice as large in the melt. The cation transport numbers (relative to the anion) were calculated for all experiments ,and for the melts also the difference between the cation mobilities. An estimation is made of the obtainable accuracy of electromigration experiments.The experiments with melts were analysed for isotope effects. The light isotopes were always enriched towards the cathode, independent of whether Li or K had the higher mobility. The magnitude of the isotope effects shows a concentration dependence, i. e. the mass effect (relative difference in mobility divided by relative difference in mass) tends to increase when an ion is dilute, as previously found for other systems. Thus for the melts with 80% Li, the mass effect is higher for K than for Li.

scholarly journals Effect of Modification on the Fluid Diffusion Coefficient in Silica Nanochannels

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 4030
Author(s):  
Gengbiao Chen ◽  
Zhiwen Liu
Keyword(s):  
Diffusion Coefficient ◽  
Diffusion Coefficients ◽  
Surface Effect ◽  
Bulk Water ◽  
Self Diffusion ◽  
Average Diffusion Coefficient ◽  
Average Diffusion ◽  
Chain Lengths ◽  
Fluid Diffusion ◽  
Self Diffusion Coefficient

The diffusion behavior of fluid water in nanochannels with hydroxylation of silica gel and silanization of different modified chain lengths was simulated by the equilibrium molecular dynamics method. The diffusion coefficient of fluid water was calculated by the Einstein method and the Green–Kubo method, so as to analyze the change rule between the modification degree of nanochannels and the diffusion coefficient of fluid water. The results showed that the diffusion coefficient of fluid water increased with the length of the modified chain. The average diffusion coefficient of fluid water in the hydroxylated nanochannels was 8.01% of the bulk water diffusion coefficient, and the diffusion coefficients of fluid water in the –(CH2)3CH3, –(CH2)7CH3, and –(CH2)11CH3 nanochannels were 44.10%, 49.72%, and 53.80% of the diffusion coefficients of bulk water, respectively. In the above four wall characteristic models, the diffusion coefficients in the z direction were smaller than those in the other directions. However, with an increase in the silylation degree, the increased self-diffusion coefficient due to the surface effect could basically offset the decreased self-diffusion coefficient owing to the scale effect. In the four nanochannels, when the local diffusion coefficient of fluid water was in the range of 8 Å close to the wall, Dz was greater than Dxy, and beyond the range of 8 Å of the wall, the Dz was smaller than Dxy.

scholarly journals Insights into the interactions and dynamics of a DES formed by phenyl propionic acid and choline chloride

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Parisa Jahanbakhsh Bonab ◽  
Alireza Rastkar Ebrahimzadeh ◽  
Jaber Jahanbin Sardroodi
Keyword(s):  
Diffusion Coefficient ◽  
Liquid Phase ◽  
Propionic Acid ◽  
Structural Parameters ◽  
Choline Chloride ◽  
Self Diffusion ◽  
Phenyl Propionic Acid ◽  
Donor And Acceptor ◽  
Experimental Values ◽  
Self Diffusion Coefficient

AbstractDeep eutectic solvents (DESs) have received much attention in modern green chemistry as inexpensive and easy to handle analogous ionic liquids. This work employed molecular dynamics techniques to investigate the structure and dynamics of a DES system composed of choline chloride and phenyl propionic acid as a hydrogen bond donor and acceptor, respectively. Dynamical parameters such as mean square displacement, liquid phase self-diffusion coefficient and viscosity are calculated at the pressure of 0.1 MPa and temperatures 293, 321 and 400 K. The system size effect on the self-diffusion coefficient of DES species was also examined. Structural parameters such as liquid phase densities, hydrogen bonds, molecular dipole moment of species, and radial and spatial distribution functions (RDF and SDF) were investigated. The viscosity of the studied system was compared with the experimental values recently reported in the literature. A good agreement was observed between simulated and experimental values. The electrostatic and van der Waals nonbonding interaction energies between species were also evaluated and interpreted in terms of temperature. These investigations could play a vital role in the future development of these designer solvents.

Self-diffusion coefficient of lithium in lithium oxide

1979 ◽  
Vol 87 (2-3) ◽  
pp. 341-344 ◽  
Author(s):  
Y. Oishi ◽  
Y. Kamei ◽  
M. Akiyama ◽  
T. Yanagi
Keyword(s):  
Diffusion Coefficient ◽  
Lithium Oxide ◽  
Self Diffusion ◽  
Self Diffusion Coefficient
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