Controlled synthesis, characterization and thermal properties of Mg2B2O5

Optimum conditions for synthesizing monoclinic and triclinic Mg2B2O5 compounds by high-temperature solid-state reactions were investigated. Mixtures composed of boric acid and magnesium oxide at MgO:B2O3 mole ratios of 1:0.25, 1:0.5 and 1:1.5 were heated for 1 hour at temperatures between 600-1050 degrees C and the formed phases were identified by XRD analysis. Monoclinic Mg2B2O5 was formed by heating at 850 degrees C for 4 hours together with minimum amounts of triclinic Mg2B2O5, while triclinic Mg2B2O5 was formed as a single phase at 1050 degrees C for the same reaction time. The products obtained at optimum conditions were subjected to a series of tests to determine their chemical compositions, particle size distributions, surface area values, IR spectra and TG/DTA patterns.