N. Mironova et al., DISTRIBUTION OF MANGANESE IONS IN MAGNESIUM-ALUMINUM SPINELS OF DIFFERENT STOICHIOMETRIES, Optical materials, 6(3), 1996, pp. 225-232
Cathodoluminescence (CL), photoluminescence (PL) and EPR spectra of na
tural and synthetic spinels have been measured. CL spectra reveal two
emission bands caused by transitions within Mn2+ ion. Relative intensi
ties of green and red emission of Mn2+ have been compared during simul
taneous excitation of tetra- and octa-coordinated manganese ions under
electron beam. Growth of relative intensity of Mn2+ CL in tetrahedral
sites has been found in common with decrease of manganese relative co
ncentration. A peculiar Mn-associated FL; which is typical for 3d(3) i
ons, has been observed in lilac natural spinel. Proceeding from positi
on of optical band, the corresponding coordination has been chosen. Si
mulating EPR spectra have been used to estimate the degree and kind of
disorder of nearest neighbours of Mn2+ ions.