Knowledge Bank

A convenient reference spectrum for wavelength calibration would be provided by a solid, obtained and stable indefinitely, exhibiting a series of sharp, symmetric absorption bands closely spaced throughout the infrared region, and providing accuracy of a few tenths wave number. The characteristics of solid solution spectra from alkali halide crystals indicate that these solutions may provide such a reference spectrum A preliminary report will be given on attempts to provide a series of calibration bands Sixteen sharp absorptions from ions in solid solution in KBr have been chosen to provide calibration peaks sparced through the region 2200 to $700cm-1$, with but one space between bands exceeding $150cm-1$. This spectrum is obtained by the addition of six compounds to the molten alkali halide, with subsequent cooling to obtain a solid solution, used either as single crystals or as disks pressed by the usual KBr technique. The frequencies and band widths in this spectrum, and the chemistry of the solid solution will be discussed.