Influence of Impurities on the Room-Temperature Coloration Processes in Alkali Halides

1970 ◽  
Vol 2 (8) ◽  
pp. 3415-3420 ◽  
Author(s):  
E. V. R. Sastry ◽  
T. M. Srinivasan
Keyword(s):  
Room Temperature ◽  
Alkali Halides ◽  
Influence Of Impurities

The influence of impurities on the dissolution of Ca- and Sr-bearing barite at room temperature

2006 ◽  
Vol 25 (1) ◽  
pp. 71-84 ◽  
Author(s):  
Xuehong Zhang ◽  
Yinian Zhu ◽  
Stober Ingrid ◽  
Bucher Kurt
Keyword(s):  
Room Temperature ◽  
Influence Of Impurities

The thermal expansion of alkali halides at low temperatures

1965 ◽  
Vol 286 (1405) ◽  
pp. 204-217 ◽  
Keyword(s):  
Low Temperatures ◽  
Room Temperature ◽  
Alkali Halides ◽  
Theoretical Models ◽  
Liquid Oxygen ◽  
Rock Salt Structure ◽  
General Behaviour ◽  
A Value ◽  
Salt Structure ◽  
Expansion Coefficients

Linear thermal expansions of eight alkali halides have been determined at liquid oxygen temperatures and at temperatures from 30 °K down to 2 °K. For temperatures T ≤ θ/20, where θ is the Debye temperature, the expansion coefficients are well represented by α = AT 3 + BT 5 . Values are reported for the Grüneisen parameter γ = 3α V/Cx , where C/V is the heat capacity per unit volume and x is the compressibility. For CsBr (b.c.c. structure) γ appears to be nearly independent of temperature, with a value of 2·0 but for the other crystals, which have the rock-salt structure, the parameter γ varies with temperature, chiefly betw een θ/10 and θ/5. At room temperature, γ lies between 1·45 and 1·7 but at low temperature this generally decreases to a value γ 0 which is ca. —0·1 for RbI, +0·3 for KCl, KBr and KI and 1·0 for NaCl and Nal; LiF does not show this decrease, γ 0 being 1·7. The values observed for γ 0 are compared with those calculated from elastic constants and their pressure derivatives and the general behaviour of γ( T ) is observed to conform qualitatively to the predictions of simple theoretical models of Born, Blackman and Barron.

14N NQR Studies of Impurity Effects on the Local Structure of NaNO2 -based Mixed Systems

2000 ◽  
Vol 55 (1-2) ◽  
pp. 219-224 ◽  
Author(s):  
S. K. Song ◽  
Y. M. Park ◽  
J. K. Jung ◽  
Y. M. Seo ◽  
S. H. Choh
Keyword(s):  
Point Defects ◽  
Room Temperature ◽  
Random Distribution ◽  
Impurity Effects ◽  
Fast Motion ◽  
Local Disorder ◽  
Mixed Systems ◽  
Low Symmetry ◽  
Influence Of Impurities

The influence of impurities on the 14N NQR lineshape of Na1-xAgxNO2 and [NaNO2]1-x-[BNO3]x (B = Na, K) at room temperature has been investigated. Carrying out spectral analysis in conjunction with classification of the local field inhomogeneities according to the structurally isomorphic, Na1-xAgxNO2 , and anisomorphic [NaNO2]1-x[BNO3]x systems, enabled an under-standing of the microscopic nature of impurity-induced local disorder. The iso-and anisomorphic systems reveal their own unique features of the impurity induced local disorder. They are charac-terized by a static, random distribution of impurities in the isomorphic system and a fast motion of the impurity-induced mobile point defects in the anisomorphic system. However, for both systems, neither a change of the 14N NQR frequency nor a multisplitting of the lines is observed because of the relatively low symmetry.

Formation of radiophotoluminescence centers at room temperature in Ag-doped alkali halides

2019 ◽  
Vol 58 (6) ◽  
pp. 062004 ◽  
Author(s):  
Hiroki Kawamoto ◽  
Masanori Koshimizu ◽  
Yutaka Fujimoto ◽  
Keisuke Asai
Keyword(s):  
Room Temperature ◽  
Alkali Halides
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