(NO TITLE).

Abstract

Crystals of alkaline earth fluorides grown by the Bridgman or to a lesser extent by the pull ing technique are frequently colored (yellow, green, or violet). The coloration can be removed by annealing the colored crystals in a graphite crucible above 1000 C, under a neutral atmosphere such as argon. Absorption spectra of colored alkaline earth fluorides are similar to those obtained by coloration with high-energy quanta or particles. The chemical preparation and purification of lead halides has proven more complicated than expected; the impurities which cause the darkening of crystals are especially elusive. Sulfur seems to be the impurity causing darkening. Dielectric measurements of CaF2, SrF2, and BaF2, are reported. (Author)

Document Details

Document Type
Technical Report
Publication Date
Dec 01, 1963
Accession Number
AD0430020

Entities

Organizations

  • Massachusetts Institute of Technology

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Absorption
  • Absorption Spectra
  • Annealing
  • Atmospheres
  • Crucibles
  • Energy
  • Fluorides
  • Graphitic Materials
  • Halides
  • High Energy
  • Impurities
  • Measurement
  • Particles
  • Sorption
  • Spectra

Readers

  • Analytical Chemistry
  • Materials Science and Engineering.
  • Systems Analysis and Design