Luminescence of Pr3+ doped K2LaCl5 microcrystals encapsulated in KCl host

Scanning electron microscopy and luminescence spectroscopy studies have shown the formation of Pr3+ doped K2LaCl5 microcrystalline phase embedded in KCl host after annealing of KCl-LaCl3 (0.5 mol.%)-PrCl3 (0.05 mol.%) at 250 °C. The luminescent characteristics of KCl-LaCl3 (0.5 mol.%)-PrCl3 (0.05 mol.%) are found to be similar with those of K2LaxPr1−xCl5 bulk crystals. The luminescence of Pr3+ ion is observed from KCl-LaCl3 (0.5 mol.%)-PrCl3 (0.05 mol.%) due to the radiative transitions within Pr3+ 4f2 configuration whereas Pr3+ 4f5d → 4f 2 emission is not revealed. Excitonic mechanism of energy transfer to the Pr3+ activator centers in KCl-LaCl3 (0.5 mol.%)-PrCl3 (0.05 mol.%) crystal is considered.