X2O3(X=B、Al、Ga)-K2O(ZnO)-Nb2O5系统玻璃生成及性质

用通常的玻璃熔融浇注或高温水淬火方法,研究了(B、Al、Ga)₂O₃-K₂O(ZnO)一Nb₂O₅系统玻璃生成能力。测定了有关玻璃的折射率、色散、密度及红外透过率等性质。实验结果表明:钾铌酸盐K(NbO₃)比锌铌酸盐Zn₂(Nb₂O₇)易形成玻璃;X₂O₃-K₂O-Nb₂O₅各系统均能形成玻璃。值得注意的是,X₂O₃含量低于30%mol(甚至可低达10%mol)时,仍然能生成玻璃。这时,Nb₂O₅含量按B³⁺、Al³⁺、Ga³⁺顺序而趋向增加(25-45%mol)。其中Al₂O₂和Ga₂O₃钾铌酸盐玻璃红外透过截止波长大于6μm;Nb₂O₅-B₂O₃-K₂O系统玻璃具有高色散、低折射率等性质,它们的密度与光性相近的其它玻璃相比又比较小。最后,根据玻璃结构参数、键参数、电负性与平均离子半径比的关系等计算结果,推断了Nb⁵⁺的配位数为四和六。Nb₂O₅在Nb₂O₅-X₂O₃-K₂O系统中赋存状态为偏铌酸盐。

Glass Formation and Properties of Glasses in the Systems X2O3 (X=B、Al、Ga)-K20(Zn0)-Nb205

Glass forming tendencies and some properties of the systems(B. Al. Ga)₂O₃-K₂O(ZnO)-Nb₂O₅ have been studied. On the basis of calculating structure parameter, bond parameter, relation between the electronegativity and the ratio of average ion radius, the coordination number of Nb was inferred to be 4 and 6 and Nb₂O₅ in the system Nb₂O₅-B₂O₃-K₂O exists as a metaniobate state.