Impact of ball milling on the cubic Sb2O3 into orthorhombic Sb2O3 and SbO2 materials – Structural and other characterization studies

The present investigation adds new information about the cubic Sb₂O₃ and orthorhombic Sb₂O₃ and SbO₂ phases to the scientific society. In this work, the Sb₂O₃ (commercial) powder was ball-milled in a tungsten carbide (WC) jar using WC balls with different diameters at 300 ​rpm for several time intervals (1, 3, 5, 10, 20, and 30 ​min and 1, 2, 5, 10, 20, and 30 ​h) and reported their findings of structural, thermal, optical, and morphology. Interestingly, the ball-milled powder undergoes phase transformation from cubic Sb₂O₃ into orthorhombic Sb₂O₃ and SbO₂ in a short duration (3–30 ​min) of ball milling. While the 0, 1, and 3 ​min ball milled samples preserve the cubic Sb₂O₃ structure, the 5 ​min ball milled sample exhibits a nearly single-phase orthorhombic Sb₂O₃ structure. Mixed phases of orthorhombic Sb₂O₃ and SbO₂ phases are seen for the 10–20 ​min ball milled samples. For a 30 ​min ball milled sample, an orthorhombic SbO₂ phase is observed. Furthermore, the 1, 3, 5, 10, 20, and 30 ​h ball milled samples retain the orthorhombic SbO₂ phase. Maximum weight loss of 34.4 ​% is noted for the commercial Sb₂O₃ powder, whereas the 1 and 3 ​min of ball-milled samples reveal the weight loss of 9.3 and 4.7 ​%, respectively. The other ball-milled samples exhibit both weight loss and weight gain in the thermogravimetric analysis (TGA) curves. The Raman features of ball-milled orthorhombic SbO₂ are quite different from those of other types of antimony-based oxides. Bar/bundle-shaped and spherical-shaped with agglomerated particles are seen for the commercial Sb₂O₃ phase and ball-milled (1 and 30 ​h) SbO₂ phase samples.