The influence of manganese cations on the structure of lead high bismuthate glasses and glass ceramics

Raman and infrared spectroscopy have been employed to investigate the glasses and glass ceramics belonging to the x[4Bi2O3·PbO](1 − x)MnO system, with x = 1 and 0.8, in order to obtain valuable information about the competitive role played by the constituent oxides in their network formation. The glass samples have been prepared by melting the mixtures corresponding to the required compositions at 1100 °C and rapidly cooling at room temperature. In order to improve the local order and to develop crystalline phases the as prepared samples were kept at 575 °C for 10 h. Both the influence of the manganese cations as well as of the heat treatment on the local order around bismuth and lead atoms have been discussed.