Structural, vibrational, and luminescent properties of pure and Ce-doped magnesium lithium aluminoborate glass

Abstract

The objective of this work was to study the properties of new vitreous samples of pure BAlMgLi and Ce-doped BAlMgLi produced by the melt-quenching method. The structural and vibrational characteristics of the samples were analyzed using x-ray diffraction (XRD), vibrational Raman spectroscopy, and vibrational Fourier transform infrared spectroscopy (FTIR). Optically stimulated luminescence (OSL) and thermoluminescence (TL) techniques were also used to identify whether the samples showed a response to ionizing radiation. XRD analyses confirmed the predominance of the amorphous phase of the samples. The Raman spectra revealed that the atomic bonds present in the material matrix are of the pyroborate and metaborate type, enabling stretching vibrations in isolated BO4 and/or Al–O or Al–O–B units. The band at approximately 810 cm−1 is characteristic of the formation of the boroxol ring, indicating that the presence of other elements in the matrix does not affect its glassy characteristics. The FTIR analyses reinforce the results found by Raman spectroscopy, because bands characteristic of low hygroscopic glasses were observed, due to the conversion of BO3 units into BO4 in triborate, tetraborate, and pentaborate groups. This conversion is due to dopant entrainment, which contributes to the high optical transparency of the samples. Their OSL and TL signals were reproducible with intensities dependent on the dopant concentration and radiation dose, with the most intense emissions resulting from 0.5% Ce concentrations.