The Luminescence of Thallium-Activated Potassium Chloride Phosphors

Journal Article · Tue Feb 23 00:00:00 EST 1960 · Proceedings of the Royal Society. A. Mathematical, Physical and Engineering Sciences

DOI:https://doi.org/10.1098/rspa.1960.0025· OSTI ID:4202951

Ewles, J.; Joshi, R. V.

New experimental investigations were made of the excitation, absorption, and emission spectra, phosphorescent decay curve characteristics, tbermoluminescence, and photoconductivity of potassium chloride phosphors activated by thallium and of the thermoluminescence of potassium chloride phosphors activated by barium, by strontium, or by thermal or mechanical strains. It is concluded that for concentrations of more than about 0.001 mol. Tl the KCl: TlCl phosphors contain a nunnber of different centers. Reasons are given for suggesting that some of these may be: (1) Tl/sup +/ ions at substitutional sites and not near to other Tl/sup +/ ions at neighboring positive ion sites, (2) TlCl/sub n/ complexes at special sites near defects or along dislocations, (3) lattice distortions produced by the incorperation of Tl/sup +/ or other foreign ions. Since the main emission peaks appearing in the thermolunninescence of KCl: Tl at 200 and 300 ction prod- K also occur in the KCl phosphors activated by bariunn, by strontiunn. or by thermal or mechanical strain, it would appear that the electron traps responsible for the phosphorescence of HCl : Tl cannot be, as Williams suggests, metastable levels in Tl ions. It is suggested that they are at lattice defects created either by Tl or other foreign ions or by thermal or mechanical strains. The complexity of the absorption, emission, and excitution spectra suggest that the existing theories (such as those of Williams and his co- workers and of Knox & Dexter) of the luminescence of HCl : Tl require further development. ( auth)

• Research Organization: Univ. of Leeds, Eng.
• Sponsoring Organization: USDOE
• NSA Number: NSA-14-010919
• OSTI ID: 4202951
• Journal Information: Proceedings of the Royal Society. A. Mathematical, Physical and Engineering Sciences, Vol. 254, Issue 1278; Other Information: Orig. Receipt Date: 31-DEC-60; ISSN 1364-5021
• Publisher: The Royal Society Publishing
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

PHYSICS
ABSORPTION
BARIUM
DECAY
DEFECTS
DEFORMATION
DENSITY
ELECTRIC CONDUCTIVITY
ELECTRONS
EMISSION
ENERGY LEVELS
EXCITATION
IONS
LATTICES
LUMINESCENCE
MEASURED VALUES
PHOSPHORS
PHOTOELECTRIC EFFECT
POTASSIUM CHLORIDES
SPECTRA
STABILITY
STRESSES
STRONTIUM
TEMPERATURE
THALLIUM
THALLIUM CHLORIDES
THERMAL STRESSES
TRAPS