Influences of La3+ and Er3+ on structure and properties of Bi2O3–B2O3 glass

Abstract Bi 2 O 3 ·2B 2 O 3 glasses doped with La 2 O 3 and Er 2 O 3 were prepared by the melting-quenching method with AR-grade oxides. IR analysis was used to investigate the glass network structure. The characteristic temperatures including the glass transition temperature ( T g ), crystallization temperature ( T p ), and melting temperature ( T m ) were estimated by DSC. The coefficient of thermal expansion ( α ), mass density ( D ), and Vickers hardness ( H v ) were also measured. The results show that the basic network structure of Bi 2 O 3 ·2B 2 O 3 glasses doped with rare-earth oxides consists of chains composed of [BO 3 ], [BO 4 ], and [BiO 6 ] units. La 2 O 3 and Er 2 O 3 act as network modifiers. As the doping concentrations of the rare-earth oxides were increased, T g increased and α decreased, indicating that a more rigid glass was obtained. Er 2 O 3 reduces the melting temperature and prevents glass crystallization. La 2 O 3 contributes to the improvement of the microhardness of Bi 2 O 3 ·2B 2 O 3 glass.