Infrared absorption due to H− ions in sodium and potassium halides. I. Anharmonic side bands of the local mode

1970 ◽  
Vol 48 (18) ◽  
pp. 2176-2187 ◽  
Author(s):  
R. W. MacPherson ◽  
T. Timusk
Keyword(s):  
Neutron Scattering ◽  
Shell Model ◽  
Infrared Absorption ◽  
Local Mode ◽  
Sodium Halides ◽  
Sodium And Potassium ◽  
Potassium Halides

New measurements and calculations of the side bands of the local-mode absorption of H− ions in the infrared are presented for the potassium and sodium halides. Some new features are observed and a shell model for the defect along with phonon data determined from neutron scattering experiments is used to satisfactorily explain the observed spectra.

Infrared absorption due to H− ions in sodium and potassium halides. II. Impurity induced absorption in the far-infrared region

1970 ◽  
Vol 48 (24) ◽  
pp. 2917-2929 ◽  
Author(s):  
R. W. MacPherson ◽  
T. Timusk
Keyword(s):  
Absorption Spectrum ◽  
Density Of States ◽  
Infrared Absorption ◽  
Far Infrared ◽  
Infrared Region ◽  
Local Mode ◽  
Defect Model ◽  
Side Band ◽  
Sodium And Potassium ◽  
Potassium Halides

Measurements and calculations of the impurity induced far-infrared absorption due to H− ions in the sodium and potassium halides are presented. The defect model which was previously determined from theoretical fits to experimental local mode and anharmonic side band data is used to predict the absorption spectrum in the far-infrared region below the reststrahlen frequency. The agreement with the observed absorption spectra is good. It is shown that certain features may be interpreted as Van Hove singularities in the unperturbed density of states of the host crystals and that other peaks in the KBr and KI spectra are due to localized resonances.

The Urbach Rule for the Sodium- and Potassium-Halides

1974 ◽  
Vol 29 (1) ◽  
pp. 145-157 ◽  
Author(s):  
Tetsuhiko Tomiki ◽  
Takeo Miyata ◽  
Hirokazu Tsukamoto
Keyword(s):  
Temperature Dependence ◽  
Acoustic Phonon ◽  
Frequency Factor ◽  
Host Lattice ◽  
Exciton Peak ◽  
Urbach Rule ◽  
Temperature Dependences ◽  
Hole Band ◽  
Sodium And Potassium ◽  
Potassium Halides

Phenomenological and physical aspects of the intrinsic tail spectra of the alkalihalides are studied referring to the new results on the intrinsic tail spectra of KBr and KI and to the temperature dependences of the lowest-energy Γ-exciton peak of the sodium- and potassium-halides. Systematically analysing the temperature dependence of the steepness parameter σs (T) of the Urbach rule for these halides, it is found that the frequency factor has the value nearly equal to the acoustic phonon energy at X or L of each host lattice and the steepness constant σs0 becomes larger in passing from fluoride to iodide. This halogen dependence of σs0 is discussed in terms of the hole band-mass of the Γ8-level.

scholarly journals The diamagnetic susceptibilities of salts forming ions with inert gas configurations II-The alkaline halides

1935 ◽  
Vol 152 (876) ◽  
pp. 342-353 ◽  
Author(s):  
G. W. Brindley ◽  
F. E. Hoare ◽  
Richard Whiddington
Keyword(s):  
Crystalline State ◽  
Experimental Methods ◽  
Inert Gas ◽  
Complete Set ◽  
Sodium And Potassium ◽  
Potassium Halides

The data so far published on the diamagnetic susceptibilities of the alkaline halides, measured for the salts in the crystalline state, are very discordant and incomplete, as reference to Table I will show. The aim in carrying out these experiments has been twofold: firstly, to obtain a complete set of values for these salts and secondly to examine more closely than has hitherto been possible how rigorously the susceptibilities of simple crystalline salts are additive. It has already been established that the susceptibilities are approximately additive, but it has not been possible to test this with exactitude because of ( a ) the large discrepancies between the results obtained by previous observers, and ( b ) the lack of data for many crystals. The discrepancies may have arisen to some extent from the different experimental methods, some of which are more accurate than others and some of which may introduce errors peculiar to themselves. We have therefore made a complete re-determination of the susceptibilities of all the alkaline halides, using the same apparatus and method under the same conditions. Since any systematic experi-mental errors will affect all our results to approximately the same extent, we shall be in a stronger position for testing the additivity of the susceptibilities than if we rely partly on our own and partly on other observers’ results. Previous investigators have measured the susceptibilities of some compounds in the crystalline state and others in solution; the latter are of no help in connexion with our problem, for an examination of the available data suggests that solutions have susceptibilities higher by several per cent, than the corresponding crystals. We cannot, therefore, arrive at any certain conclusion by using results obtained partly for crystals and partly for solutions. 2—Method The method previously described has been used to obtain a complete set of values for the susceptibilities of the alkaline halides. Although slight modifications have been made from time to time, the apparatus has remained, in essentials, the same as when used for the measurement of the susceptibilities of the sodium and potassium halides.

Interplay of Lewis acidity, intramolecular O→Sn interactions and selectivity: organotin-functionalized crown ethers as ditopic hosts for sodium and potassium halides

2018 ◽  
Vol 54 (7) ◽  
pp. 739-742 ◽  
Author(s):  
Alain Charly Tagne Kuate ◽  
Muhammad Moazzam Naseer ◽  
Michael Lutter ◽  
Klaus Jurkschat
Keyword(s):  
Crown Ethers ◽  
Lewis Acidity ◽  
Sodium And Potassium ◽  
Potassium Halides

Not only ditopic complexation, but also selectivity has been realized by increasing the Lewis acidity of tin atom in organotin-functionalized crown ethers.

scholarly journals Nuclear structure of Ge76 from inelastic neutron scattering measurements and shell model calculations

2017 ◽  
Vol 95 (1) ◽  
Author(s):  
S. Mukhopadhyay ◽  
B. P. Crider ◽  
B. A. Brown ◽  
S. F. Ashley ◽  
A. Chakraborty ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Shell Model ◽  
Nuclear Structure ◽  
Inelastic Neutron Scattering ◽  
Inelastic Neutron ◽  
Model Calculations ◽  
Scattering Measurements
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