|Author||Messner, D. ♦ Smakula, A.|
|Source||United States Department of Energy Office of Scientific and Technical Information|
|Subject Keyword||METALS, CERAMICS, AND OTHER MATERIALS ♦ ABSORPTION ♦ BARIUM FLUORIDES ♦ BLEACHING ♦ CALCIUM FLUORIDES ♦ COLOR ♦ COLOR CENTERS ♦ CRYSTALS ♦ DEFECTS ♦ ELECTRON BEAMS ♦ LATTICES ♦ LOW TEMPERATURE ♦ PHOTOCHEMISTRY ♦ RADIATION EFFECTS ♦ SPECTRA ♦ STRONTIUM FLUORIDES ♦ VARIATIONS ♦ X RADIATION|
|Abstract||Single crystals of CaF/sub 2/, SrF/sub 2/, and BaF/sub 2/ were colored by x rays (150 kv) and high-energy electrons (2.5 Mev). Five color-center bands in CaF/sub 2/ and SrF/sub 2/ and nine in BaF/sub 2/ were observed in the spectral region between 0.175 and 0.8 mu . At room temperature the bands in CaF/sub 2/ are well resolved; whereas, those in SrF/sub 2/ and BaF/sub 2/ overlap. At -190 and -255 deg C, the bands sharpen but generally do not shift, except the 580-m mu band in CaF/sub 2/, which shifts toward longer wavelengths. Photochemical bleaching of the strongest band shows a certain influence on the others. Three bands could be correlated to the Mollwo relation with the exponent 3.85. A possible correlation of the absorption bands to certain models is discussed. (auth)|
|Learning Resource Type||Article|
|Publisher Department||Massachusetts Inst. of Tech., Cambridge|
|Organization||Massachusetts Inst. of Tech., Cambridge|
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