Exchange reactions of alkali atoms with alkali halides: a collision complex mechanism

1967 ◽  
Vol 44 ◽  
pp. 108 ◽  
Author(s):  
W. B. Miller ◽  
S. A. Safron ◽  
D. R. Herschbach
Keyword(s):  
Alkali Halides ◽  
Complex Mechanism ◽  
Exchange Reactions ◽  
Collision Complex ◽  
Alkali Atoms

Atomic and molecular emission following fracture of alkali halides: A dislocation driven process

1991 ◽  
Vol 6 (1) ◽  
pp. 112-125 ◽  
Author(s):  
J.T. Dickinson ◽  
L.C. Jensen ◽  
S.C. Langford ◽  
J.P. Hirth
Keyword(s):  
Heat Treatment ◽  
Molecular Species ◽  
Neutral Particle ◽  
Alkali Halides ◽  
Time Intervals ◽  
Neutral Species ◽  
Free Surfaces ◽  
Alkali Atoms ◽  
Fracture Event ◽  
Long Time

During and following fracture of a number of materials, the emission of photons, electrons, ± ions, and neutral species are observed; these emissions are collectively known as fracto-emission. In this work, we present measurements of the neutral particle emission following fracture of two single crystal fcc alkali halides: NaCl and LiF. We observe no measurable emission attributable to release during the fracture event itself. However, after relatively long time intervals of ∼0.5–250 ms, we observe rapid bursts of alkali atoms, as well as molecular species which include NaCl and (LiF)n where n = 1,2,3. Bursts of alkali containing species also occur during loading prior to fracture and for unloaded specimens during heat treatment. We argue that these bursts are due to energetic emergence (“popout”) of dislocations at free surfaces.

Photon-stimulated desorption of excited alkali atoms from alkali halides following core-level excitation

1991 ◽  
Vol 243 (1-3) ◽  
pp. A90
Author(s):  
P.H. Bunton ◽  
R.F. Haglund ◽  
D. Liu ◽  
N.H. Tolk
Keyword(s):  
Alkali Halides ◽  
Core Level ◽  
Alkali Atoms

Molten Mixtures of K, Na Formates with Alkali Halides. Note II * Concerning the exchange reactions

1970 ◽  
Vol 25 (1) ◽  
pp. 56-58 ◽  
Author(s):  
Dante Leonesi ◽  
Giammario Piantoni ◽  
Paolo Franzosini
Keyword(s):  
Saddle Points ◽  
Alkali Halides ◽  
Exchange Reactions ◽  
Visual Method ◽  
Ternary Eutectics ◽  
Solid Liquid

Abstract By employing a visual method, solid-liquid equilibria were studied in a wide series of molten mixtures in order to draw the maps of the reciprocal systems formed with K, Na formates and bromides or iodides. Within the accessible portion of each system, five crystallization regions, three ternary eutectics and two saddle points were identified. The interdependence between the areas of some crystallization regions and the sizes of the halogen ions was put into evidence.

A Study of Solid-State Anion Exchange between Some p-Aminophenol Hydrohalides and Twelve Alkali Halides by Infrared Spectroscopy

1971 ◽  
Vol 25 (4) ◽  
pp. 465-471 ◽  
Author(s):  
D. M. Drew ◽  
J. T. van Gemert
Keyword(s):  
Matrix Material ◽  
Alkali Halides ◽  
Exchange Reactions ◽  
Rate Of Reaction ◽  
The Matrix ◽  
Crystal Type ◽  
Complete Exchange ◽  
Lattice Energies ◽  
Type Lattice ◽  
Sodium And Potassium

The exchange of the anion of three hydrohalides of p-aminophenol and its N-methyl and N-benzyl derivatives has been studied by ir spectroscopy in Nujol mulls and pressed alkali halide disks. The vibrations involving the nitrogen atom are affected by the nature of the anion to an extent which makes it possible to detect the occurrence of exchange reactions. Normal grinding and pressing conditions can lead to complete exchange with the halide ion of the matrix material. The trend of exchange which is apparent for the organic compounds in sodium and potassium halides is reversed in rubidium and cesium halide matrix materials, and the presence of moisture in the grinding stage enhances the rate of reaction in most cases. Possible mechanisms are discussed in terms of the physical properties of the compounds involved, of which the main influencing factors appear to be the crystal type, lattice energies, relative ionic dimensions, and pressure induced transitions.

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