NANO-CRYSTALLITES FORMATION AND EU3-SULFATE GLASSES( LUMINESCENCE IN ZINC BORO)

In zinc borosulphate glasses (ZnSO4:B2O3 binary system) nano-crystalli tes formation is observed which can be attributed to homogenous nuclea tion process and the size of the crystallites formed is in the range 4 0-50 nm. Using IR spectroscopy studies, it has been found that the gla ss-ceramics region consists of tetrahedral berates (BO4)(5-) while the glassy region is made of triangular berates (BO3)(3-) and boroxyl rin g (B3O6)(3-) networks. The profound dependence of nucleation propertie s on the halides added in the glass composition can be explained in te rms of an inductive effect. The Eu3+ ion in this glass system yields i ntense D-5(0) --> F-7(J) emission. Also it has been found that the Ome ga(2) and Omega(4) Judd-Ofelt intensity parameters are very much depen dent on the covalent surroundings of the Eu3+ luminescent centre. Vari ous results based on these are discussed.