【摘要】 研究了P₂O₅-BaO-Nb₂O₅-Al₂O₃系统玻璃的形成,给出了玻璃形成范围图。P₂O₅为20mol％仍可形成玻璃。 研究了该系统玻璃的折射率、色散、转变温度、软化温度,线膨胀系数、热光常数及可见光区光透过和组成之间的关系。 应用原子共价半径-电荷数和键参数、电负性差-共价半径比以及单键强度讨论了Nb₂O₅在玻璃形成中的作用,并与姜中宏给出的玻璃形成系统图做了比较,认为Nb₂O₅是中间体。 讨论了该系统玻璃中铌的价态和着色。Nb⁵⁺无色,Nb³⁺使该系统玻璃着蓝色。基础玻璃较强的酸性和还原条件是Nb³⁺存在的关键条件。更多还原

【Abstract】 The formation and properties of glasses in P₂O₅-BaO-Nb₂O₅-Al₂O₃ system are studied andtheir formation ranges shown.Glasses can be formed when containing 20 mol% P₂O₅.Therelations between glass composition and refractive index n_D,dispersion n_F-n_C,transfor-mation temperature T_g,softening temperature T_f,thermal expansion coefficient a,ther-mal optic constant W and visible light transmission are studied. The role of Nb₂O₅ in glass-forming process is discussed by use of atomic covalent ra-dius dependence of charge number,bond-parameter,electronegative difference dependenceof atomic covalent radius ratio,and single bond strength.Comparing our experimental re-sults with Jiang Zhonghong’s glass-formation figures,we consider that Nb₂O₅ is a interme-diate body. Valence and colour of niobium are also discussed.Nb⁵⁺ ions are colourless,but Nb³⁺ ionsare blue.The acidity of basic glass and the reductive condition are the key points of theexistence of Nb³⁺ ion.更多还原