The influence of gadolinium on the thermal properties of bioactive glasses

Abstract Rare Earth (RE)-containing bioactive glasses has recently gained more relevance in the field of biomaterials due to the unique optical, electronic, and chemical properties of the RE elements. In this work, the influence of gadolinium in the thermal properties of bioactive glasses based on the SiO2-Na2O-CaO-P2O5 containing different Na/Ca ratio was studied. The glasses were obtained by melting-quenching, and their properties were evaluated by differential thermal analysis, X-ray diffraction, and scanning electron microscopy. The results evidenced that Gd tends to increase the working temperature (Tc-Tg) in Ca-rich glasses, which leads to a less tendency to devitrification. On the other hand, in Na-rich glasses, Gd did not play an essential role in crystallization, and the thermal properties of Gd-containing Na-rich glasses were similar to their counterparts. In conclusion, we suggested that it is possible to control the influence of Gd in the glass devitrification by changing the Na/Ca ratio in the glass composition. These results may be interesting for further works to which crystallization may be either a desired or undesired phenomena.