Liquidus Surface and Isothermal Section Diagram at 973 K in the BaO-Fe₂O₃-(0∼50 mol%)B₂O₃ Pseudo-ternary System

Abstract

The isothermal section at 973 K and the liquidus surfaces of the phase diagram of the pseudo-ternary BaO-Fe₂O₃-B₂O₃ system were determined in a composition range of less than 50 mol%B₂O₃ using the thermal analyses and X-ray diffraction. The liquidus surface which is in equilibrium with Fe₃O₄ spreads over a wide composition range, while that in equilibrium with BaO·6Fe₂O₃ is long and tapers to BaO·B₂O₃. The pseudo-ternary BaO-Fe₂O₃-B₂O₃ compound does not exist in the composition range investigated. The ternary eutectic reaction is L→BaO·6Fe₂O₃+BaO·B₂O₃+3BaO·B₂O₃, occurring at 1033 K at the composition 48 mol%BaO-19 mol%Fe₂O₃-33 mol%B₂O₃.