Abstract of Publication No. 445
U. Rogulis, S. Schweizer, J.-M. Spaeth, E. V. D. van Loef, P. Dorenbos, C. W. E. van Eijk, K. Krämer and H. U. Güdel
In undoped and Ce3+-doped LaCl3 EPR has been detected
in the X-ray luminescence (XL-EPR) in K-band (25 GHz) at 1.5 K. Two
excited triplet states with different EPR parameters and spectral shapes could
be separated, both triplet states have been attributed to "out-of-plane"
self-trapped excitons (STE) in LaCl3. No EPR signals of VK
centres (self-trapped holes) could be detected in undoped or
Ce3+-doped LaCl3 after X-irradiation at low temperatures.
X-irradiation of undoped LaCl3 creates also an EPR spectrum which can
be tentatively attributed to F-type defects. The scintillation mechanism is