Understanding the solubility and crystallization of molybdenum in high-sodium borosilicate glasses: effect of lanthanum oxide

The simplified 8-oxide system (SiO2-B2O3-Na2O-Al2O3-CaO-TiO2-MoO3-La2O3) has been prepared under two types of cooling methods, and analyzed with XRD, Raman and SEM to investigate the effect of the La2O3 addition on the crystallization tendency of MoO3 in high-sodium borosilicate glasses. The results showed that the crystalline phase of Mo is α-Na2MoO4 and La2O3 inhibits the α-Na2MoO4 crystallization. The loading capacity of MoO3 increased from 1 to 4 wt% as La2O3 content from 1% to 16 wt%. However, high La2O3 content (20 wt%) generated the oxyapatite crystal phase. These results demonstrate that a modest amount of La2O3 facilitate the MoO3 incorporate in borosilicate glasses.