EXCITON MIGRATION IN QUASI-ONE-DIMENSIONAL CRYSTALS - ANTIFERROMAGNETIC CSMNCL3.2H2O

Pure and doped antiferromagnetic CsMnCl3.2H2O (CMC) crystals have been studied in the temperature range 4.2-300 K. With an increase in temperature the luminescence time and intensity of doped CMC crystals (1% and 0.1% Cu2+) decrease. The exciton-emission quenching is associated with exciton migration and trapping. The emission decay kinetics is approximated by the calculated curves obtained using the Kenkre and Onipko, Malysheva, and Zozulenko theories. The exciton hopping (W) and trapping (U) rates have been defined. Exciton trapping by the Cu2+ traps in CMC is inefficient. The dependences W(T) and U(T) are given for two dopant concentrations in CMC obtained in the temperature range 77-237 K.