Emission Of KCl Research Articles

Magnetic Circular Polarization ofF-Center Emission in KCl

Magnetic Circular Polarization of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>F</mml:mi></mml:math>-Center Emission in KCl

Luminescence from perturbed exciton states

The luminescence of KI(Tl), KBr(Tl), and KCl(Tl) has been investigated at 20°, 80° and 300°K for excitation in the A and D bands. The data indicate that two different centers are necessary to explain the emission. It is suggested that at least one emission band in KI(Tl) and KBr(Tl) results from electronic transitions on the negative ions surrounding the thallous ion. The corresponding emission in KCl(Tl) is not evident. It is also suggested that the emitting center may have the same symmetry as the center responsible for the intrinsic emission in these crystals.

Some Optical Properties of Lead Activated Potassium Halide Phosphors

Absorption, emission and excitation spectra of KCl:Pb and KBr:Pb have been measured at various temperatures. These observed spectra are similar to those of KCl:Tl, and the absorption bands seemed to be due to transitions in Pb ++ ions which occupies the normal positive ion sites. The two principal excited states are 1 P 1 and 3 P 1 of Pb ++ ion. 273 mµ absorption, 345 mµ emission in KCl:Pb and 302 mµ absorption, 365 mµ emission in KBr:Pb are attributed to 3 P 1 – 1 S 0 transitions perturbed by surrounding host lattice ions. The excitation to 1 P 1 state does not manifest any dstinct emission which is different from the case of Tl activated phosphors. The near ultra-violet emission suffers violent thermal quenching at room temperature, and the activation energies of these nonradiative process are found to be 0.28 eV and 0.18 eV for KCl:Pb and KBr:Pb, respectively. Several discussions using a single configuration coordinate model are given.