Characterisation of pure and Pr doped BiB3O6 glasses prepared under different thermal conditions

Abstract In this work the properties of BiB3O6 (BIBO) glasses prepared at different thermal conditions are analysed. The effect of Pr3+ ions on the optical, compositional and structural properties of the BIBO glasses is also studied. The influence of different thermal treatments and Pr doping on the absorption, emission, structure and dielectric constant of these materials is reported. The main effects of increasing the maximum synthesis temperatures have been found both in the phase separation and on the optical spectra. In the case of BIBO glasses prepared under maximum temperatures near the melting point corresponding to stoichiometric BIBO (730 °C) the material was transparent with slight greenish colour. When the synthesis maximum temperature is increased up to 900 °C an absorption band located at 465 nm appears. If the maximum temperature is increased further up to 1050 °C the same absorption band is still present. However, in this case there is a clear phase separation: one reddish semitransparent material and another white opaque compound. Pr ions were successfully introduced in the glass matrix in all the cases. All the Pr-doped glasses analysed showed the characteristic emission and absorption bands from Pr3+. Varying the maximum temperatures under which the glasses were prepared do not seem to have any effect on the absorption and emission properties of the Pr3+ ions inside the BiBO glass host. Concerning to the chemical composition of the glasses, quantitative ICP chemical analysis showed that the stoichiometry of the material is better preserved versus different maximum synthesis temperatures in the case of Pr-doped glasses indicating that Pr3+ has a noticeable influence on the chemical composition of the glasses. XRD analysis do not show important differences amongst the different glasses submitted to different maximum synthesis temperature. This would indicate that in our case the chemical environment is not considerably distorted under different thermal preparation conditions. Analysis on the dielectric constant indicates a pronounced effect of the Pr3+ on its value for different glasses.