Mykhaylo Shpotyuk

A correlation ratio between a glass transition temperature Tg and average bond energy E (obtained for chalcogenide glasses in L. Tichý & H. Tichá [J. Non-Cryst. Solids, 189, 1995]) was critically analyzed in this paper. As a result, this ratio was shown to have been obtained using incorrect calculations of the average bond energy E through inappropriate application of different averaging procedures for different terms of this parameter and, therefore, it cannot be used in practice. A mathematical algorithm for calculating the average energy bonding was adjusted by the atom-averaging procedure for the both energy of the “network part of a matrix” Ec (energy of heteropolar bonds) and energy of a "residual matrix" Erm (energy of homopolar bonds), as well as considering the impossibility of forming covalent chemical bonds between cations of different type. It was stated that the linear ratio between the glass transition temperature Tg and energy bonding E can be obtained by the ratio Tg ≅ 326∙(E – 0.94) and this claim was proved for 145 typical representatives of the covalent-bonded network chalcogenide glasses (Ge-As-S/Se-type systems).

The zinc sulfide (ZnS) thin films were prepared on glass substrates by chemical bath deposition using the aqueous solutions of zinc chloride, thiourea, pH regulator and complexing agent (ammonia and hydrazine hydrate, trisodium citrate or sodium hydroxide). The calculations of boundary conditions for formation of zinc sulfide and zinc hydroxide were made at various zinc salt concentrations with different complexing agents. The structural, morphology and optical properties of the ZnS thin films were investigated. The thickness of ZnS films was measured and the recalculation of zinc mass per cm2 of the substrate surface was held for comparison. The deposition mechanism is discussed.