Lyamayev V. Luminescent properties of crystalline and glassy lithium tetraborate doped with manganese and silver

Thesis is devoted to detailed studies of luminescent properties of lithium tetraborate Li2B4O7 doped with manganese and silver. Dependency of the thermoluminescence and x-ray luminescence of single crystal, polycrystalline and glassy Li2B4O7:Mn on dopant concentration has been obtained. Luminescent properties of glassy and crystallized compounds in the composition range (Li2O·2B2O3):Mn - (Li2O·2B2O3 + 16,7 mol.% B2O3):Mn have been studied. The drastic increase of the thermoluminescence and x-ray luminescence intensity of the crystallized samples starting from 7 mol.% B2O3 excess is explained. Type of thermoluminescence kinetics of single crystal and polycrystalline Li2B4O7:Mn, Li2B4O7:Ag has been determined. The results of the fractional glow technique application have shown that there are groups of traps with continuous distribution of activation energy exist in these materials. Within the framework of Randall-Wilkins theory kinetic parameters of traps have been determined. Obtained models satisfactory reproduce experimental glow curves of the studied samples recorded at linear heating rates ranging from 0,005 K/s to 3 K/s.