Effect of copper valence on the glass structure and crystallization behavior of Bi-Pb-Cu-O glasses

Bi0.43Pb0.35Cu0.22Oy glasses with different Cu+ contents were prepared by melting at different temperatures. The glass structure consists of [BiO3] and [BiO6] units and the ratio of [BiO3]/[BiO6] increases with increasing Cu+ content. The glass transition temperature, the first crystallization temperature peak, and the thermal stability of the glasses decreases with increasing Cu+ content. The value of the activation energy, E-g, varies as a function of the Cu+ content. The crystallization mechanism in the glasses is closely related to the glass structure, which is mainly affected by the Cu+ content.