摘要
Borosilicate glasses and glass ceramics in the system 30Na2O-2Al2O3-25SiO2-xFe2O3(43-x)B2O3 (x = 0 - 20 mol%) have been prepared and studied by distinguished techniques. X-ray diffraction (XRD), transmission electron microscope (TEM), electron diffraction pattern (EDP) and SEM experiments are applied to explore the induced structural changes. Nanometer-sized species of polycrystalline structure are formed particularly in low Fe2O3 containing glasses. The size of the crystallites is found to depend on Fe2O3 concentrations. It is ranged from 10 to 33 nanometers. Structurally, these materials are suggested to contain different components, crystalline component and an interfacial component which situated between the crystallized domains. Presence of these components affects the atomic arrangement without short- or long-range order. An intermediate range ordered structure is dominant in glass ceramics of Fe2O3 2O3 concentration, since more disordered structure of lower size is present. These structural changes are found to be connected with the role of Fe2O3 and Na2O in glasses. Na2O is the strong glass modifier in the studied composition region, while Fe2O3 is consumed also as a modifier in composition of 2O3 is mainly dominant in the composition region of higher iron oxide concentration (8 - 20 mol%).
Borosilicate glasses and glass ceramics in the system 30Na2O-2Al2O3-25SiO2-xFe2O3(43-x)B2O3 (x = 0 - 20 mol%) have been prepared and studied by distinguished techniques. X-ray diffraction (XRD), transmission electron microscope (TEM), electron diffraction pattern (EDP) and SEM experiments are applied to explore the induced structural changes. Nanometer-sized species of polycrystalline structure are formed particularly in low Fe2O3 containing glasses. The size of the crystallites is found to depend on Fe2O3 concentrations. It is ranged from 10 to 33 nanometers. Structurally, these materials are suggested to contain different components, crystalline component and an interfacial component which situated between the crystallized domains. Presence of these components affects the atomic arrangement without short- or long-range order. An intermediate range ordered structure is dominant in glass ceramics of Fe2O3 2O3 concentration, since more disordered structure of lower size is present. These structural changes are found to be connected with the role of Fe2O3 and Na2O in glasses. Na2O is the strong glass modifier in the studied composition region, while Fe2O3 is consumed also as a modifier in composition of 2O3 is mainly dominant in the composition region of higher iron oxide concentration (8 - 20 mol%).
