Thermodynamically Consistent p-T Phase Diagram of Boron Oxide B2O3 by in Situ Probing and Thermodynamic Analysis

Although boron oxide B2O3 is an archetypical glass-forming substance of large industrial and fundamental importance, its phase diagram remains controversial. In the present work, the p-T phase diagram of B2O3 has been constructed based on in situ experimental data up to 8 GPa and 1900 K and thermodynamic analysis. In contrast to the previous studies, the proposed phase diagram represents only thermodynamic equilibria (reversible transformations in experiments) between crystalline (alpha, beta) and liquid states, not influenced by kinetic phenomena.