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

The absorption and luminescence excitation spectra of the quasi-one-dimensional antiferromagnet CsMnCl3. 2H(2)O (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 or. 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). (C) 2001 Elsevier Science B.V. All rights reserved.