2016-Sustainable Industrial Processing Summit
SIPS 2016 Volume 9: Molten Salts and Ionic Liquids, Energy Production
| Editors: | Kongoli F, Gaune-Escard M, Turna T, Mauntz M, Dodds H.L. |
| Publisher: | Flogen Star OUTREACH |
| Publication Year: | 2016 |
| Pages: | 390 pages |
| ISBN: | 978-1-987820-24-9 |
| ISSN: | 2291-1227 (Metals and Materials Processing in a Clean Environment Series) |
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Solidification As A Transition From Classical To Quantum Motion Of The Atoms Owing To Freezing Of Atomic Freedom Degrees
Alexei Potapov1; Valery Pavlov2;1INSTITUTE OF HIGH TEMPERATURE ELECTROCHEMISTRY, Ekaterinburg, Russian Federation; 2URAL STATE MINING UNIVERSITY, Ekaterinburg, Russian Federation;
Type of Paper: Regular
Id Paper: 139
Topic: 13
Abstract:
Under cooling from the critical temperature Tcr to T0 = Tm/2 (Tm - melting point) actual processes of solidification are slowed down by about 20 orders of magnitude. The characteristic time  (e.g., structure relaxation time according to Maxwell), increases from about the oscillation period of the atom (~10-13 s) to a year and extends beyond the measuring capability. Viscosity increases from about 10-4 Pa·s to 1016 Pa·s, the diffusion coefficient decreases from 10-7 to 10-27 m2/s, etc.
At the classical motion of atoms (molecules), all our molecular dynamics simulations gave liquid-like values of D even if the temperature was low enough, T << Tm [1, 2]. The rate of processes from Tcr to T0 slows down not 20, but approximately 2 orders of magnitude only, as in the gases. The motion of particle remains a drift and activationless (EA < RT), no any tendency to solidification is observed. The results of the other authors are similar.
The real stiffness of the structure and solidification are obtained only if the quantum “freezing” of atomic freedom degrees is taken into account in the computer model. In the crystals, not less than 10% of the atoms are “frozen” ones. They are at zero energy level, i.e. have zero energy. If they are considered to be fixed, the model yields the real solidification and the real stiffness of the lattice.
Literature
1. Pavlov V., Potapov A. Hardness of a crystal lattice as a consequence of quantum “freezing” of atomic degrees of freedom. Z. Naturforsch. (2008) 63A, S.329-338.
2. Pavlov V.V. On the crisis of the kinetic theory of liquids and solidification. Ekaterinburg, USMU, 1997, 394 p. // Website: Pavlovvalery.ru