OPTICAL STUDY OF MN2+ IONS ENVIRONMENTS IN FLUOROCHLOROZIRCONATE AND FLUOROBROMOZIRCONATE GLASSES

Some manganese doped fluorozirconate, fluorochloro- and fluorobromozir conate glasses have been prepared following and improving some standar d methods. Electron probe microanalysis has been carried out to obtain the actual composition of the samples. The optical properties of Mn2 ions, including steady state excitation and emission, and luminescenc e decay have been studied. Values of the crystal field and Racah param eters have been estimated from the excitation data. The results have b een interpreted in terms of the progressive substitution of the fluori ne ions in the first coordination shell of Mn2+ by chlorine or bromine ions. A concentration of about 6 at% of chlorines or bromines with re spect to the total number of halide ions is enough to have most of the Mn2+ ions coordinated to only chlorines or bromines.