Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

THE TRAPPING OF ELECTRONS AND HOLES IN MIXED CRYSTALS. Technical Report 171

Technical Report ·
OSTI ID:4760203
Electrons and holes were produced in mixed crystals of kCl-KBr and KCl- RbCl solid solution systems by irradiation with 3-Mev electrons at --190, --80, and 20 deg C with doses 10/sup 5/s to 10/sup 6/ rads. The optical absorption resulting from the trapping of electrons and holes was measured at --190 deg C to reduce bleaching. The mixed crystals of KCl-KBr and KCl-RbCl irradiated at liquid-nitrogen temperature contained F, F', K, and V/sub 1/ centers. The F and K centers appeared at --80 deg C while at 20 deg C irradiations the F, k, and M bands were observed. Some other bands were also observed but not studied. The Mollwo relation lambda = const. d/sup n/) is not valid for the shift of the maximum of all bands observed, possibly because of lattice distortion. The center frequency of the F' band shifted with composition opposite to the F-band deviation. In pure crystals the center frequency of the F' band was found to be lower than previously observed. The half-width of the F band is greater in mixed crystals -its maximum approximately corresponding to the microhardness maximum and the maximum deviation from iinear of the exciton band-edge shift. The V/sub 1/ band half-width in the KCl-RbCl system decreases contrary to that in KCl-KBr. Intensity of the F band-versus -compositlon curves for KCl-KBr exhibit both a relative maximum and minimum, but in KCl-RbCl only a deep minimum. In no case did a mixed crystal color more than pure KBr, contrary to what might be expected from the large distortions present. Curves for the F' and V/sub 1/ bands follow the general pattern of those of the F band but with reduced intensity. (auth)
Research Organization:
Massachusetts Inst. of Tech., Cambridge. Lab. for Insulation Research
NSA Number:
NSA-17-003481
OSTI ID:
4760203
Report Number(s):
NP-12198
Country of Publication:
United States
Language:
English

Similar Records

COLOR CENTERS IN MIXED CRYSTALS OF ALKALI HALIDES
Journal Article · Sun Mar 31 23:00:00 EST 1963 · Physical Review (U.S.) Superseded in part by Phys. Rev. A, Phys. Rev. B: Solid State, Phys. Rev. C, and Phys. Rev. D · OSTI ID:4724169

PHOTOCHEMICALLY PRODUCED COLOR CENTERS IN KCl AND KBr
Journal Article · Fri Mar 31 23:00:00 EST 1961 · Physical Review (U.S.) Superseded in part by Phys.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 · OSTI ID:4031968

COLOR CENTERS PRODUCED IN KCl AND KBr BY PROLONGED X-IRRADIATIONS AT LOW TEMPERATURES
Thesis/Dissertation · Mon Dec 31 23:00:00 EST 1962 · OSTI ID:4013992