PHOTOCHEMICALLY PRODUCED COLOR CENTERS IN KCl AND KBr

Journal Article · Sat Apr 01 04:00:00 EST 1961 · Physical Review (U.S.) Superseded in part by Phys. Rev. A, Phys. Rev. B: Solid State, Phys. Rev. C, and Phys. Rev. D

DOI:https://doi.org/10.1103/PhysRev.122.18· OSTI ID:4031968

Cape, J A

KCl and KBr crystals were exposed to unfiltered mercury arc radiation at 15 deg K. lf an "OH" band was present in the crystals before irradiation, the ultraviolet irradiation produced an optical absorption spectrum similar to that produced by x-rays at 15 deg K. The optical absorption spectrum and the changes in the absorption produced by annealing at higher temperatures were measured and compared with the spectra observed during similar annealing of x-irradiated crystals. In KCl the 235-m mu band, formed by the uv irradiation, bleaches thermally at 56 deg K as does the 335-m mu H band of x-irradiated KCl. In KBr the 381-m mu band bleaches in steps at 35 deg , 46 deg 56 deg , and 80 deg K as compared with the 381-m mu H band in x-irradiated KBr which bleached at 30 , 46 deg 56 deg , and 80 deg K. In both KCl and KBr the V/sub 1/ band appears with the disappearance of the H band. Illumination in the V/sub 1/ band causes regeneration of the H band as occurs in x-irradiated KCl and KBr. In both KCl and KBr the photoproduced H band grows by about 10% at approximately 25 deg K. It is concluded that the H centers bleach thermally by diffusing to and combining with other color centers. Recombination with F and alpha centers annihilates the H centers and leads to the formation of V/sub K/ centers, while recombination with a third center (possibly a positive-ion vacancy) results in the formation of V/sub 1/ centers. U, U/sub 1/, U/sub 2/, O/sup -/, and alpha centers are produced by the uv irradiation as well as F and H centers. The photoproduced F band may be bleached optically with negligible effect on the H band. (auth)

• Research Organization: Univ. of Illinois, Urbana
• NSA Number: NSA-15-015634
• OSTI ID: 4031968
• Journal Information: Physical Review (U.S.) Superseded in part by Phys. Rev. A, Phys. Rev. B: Solid State, Phys. Rev. C, and Phys. Rev. D, Journal Name: Physical Review (U.S.) Superseded in part by Phys. Rev. A, Phys. Rev. B: Solid State, Phys. Rev. C, and Phys. Rev. D Vol. Vol: 122; ISSN PHRVA
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ABSORPTION
ANNEALING
ANNIHILATION
CHEMISTRY
COLOR
COLOR CENTERS
CRYSTALS
DIFFUSION
LATTICES
MEASURED VALUES
MERCURY
PHOTOCHEMISTRY
POTASSIUM BROMIDES
POTASSIUM CHLORIDES
PRODUCTION
RADIATIONS
SPECTRA
ULTRAVIOLET RADIATION
VACANCIES