Absorption and luminescence of CsMnCl3·2H2O crystals doped with Cu2+

The absorption and luminescence excitation spectra of the quasi-one-dimensional antiferromagnet CsMnCl3 · 2H2O (CMC) doped with copper ions (0–3%) are studied in the temperature range 4.2–80 K. Impurity absorption is detected in crystals: it is weak in the infrared (11 000 cm−1) and strong in the ultraviolet (20 000–33 000 cm−1) ranges. The possibility of excitation exchange between the high-energy states of the impurity and matrix is discussed. Computer simulation of the exciton migration in a doped CMC crystal is performed, taking into account the impurity–matrix transitions of excitations in the high-energy states. The conclusion is derived that the energy transfer by an electron excitation from Mn2+ to Cu2+ occurs only in the lowest excited state (due to migration of excitons and their trapping by the Cu2+ ions).