16. Phosphate Glasses

This chapter is dedicated to the study of phosphate glasses, from their fundamental aspects to their most relevant applications today. \(\mathrm{P_{2}O_{5}}\)-based glasses have experienced a continuously increasing number of published works in the last decades and still they possess a bright potential. Their sometimes intricate structure has made their study a quite relevant field for the glass science community, which attracts more and more researchers. In addition, the associated difficulties in their preparation on a large scale have led to the development of specific methods, such as those used for the melting of Nd-laser glasses. They are particularly known to have a low chemical durability, though the progress in the optimization of their composition demonstrates that can be very competitive and, in this respect, we will also pay attention to the improvement of their properties as a result of their nitridation. The structure and main physicochemical properties of phosphate glasses will be reviewed, highlighting the most relevant and well-known applications existing nowadays, such as sealing and laser glasses, biomedical glasses, and solid electrolytes or for the storage of wastes.