Abstract
The optical absorption spectra of single crystals of sodium chloride, potassium chloride, and potassium bromide from various sources (Harshaw, Optovac, and NRL) have been measured from the visible region to the fundamental edge. Bands are found at 185 m\ensuremath{\mu} in NaCl, at 204 m\ensuremath{\mu} in KCl, and at 214 m\ensuremath{\mu} in KBr. The positions of the bands satisfy an Ivey relation, $\ensuremath{\lambda}=691{d}^{0.95}$, where $d$ is the lattice parameter in angstroms. These bands are associated with the presence of hydroxyl ions in the lattice. When NaCl is additively colored, a hydride ion absorption ($U$ band) appears which is proportional to the 185-m\ensuremath{\mu} band absorption in the crystal before coloration. The $F$ band produced in NaCl and KCl by ionizing radiation is also proportional to the initial hydroxyl ion band absorption. It is found that the hydroxyl ion absorption band can be removed by the addition of certain impurities to the melt.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call