Synthesis of Magnesium–Aluminum Spinel at High Pressures and High Temperatures in the Mg2B2O5–Al, MgO–Al2O3, and MgO–Al2O3–Al Systems

The possibility of MgAl2O4 synthesis at high pressures and high temperatures (by the HPHT method) has been studied for за Mg2B2O5–Al, MgO–Al2O3, and MgO–Al2O3–Al systems. It has been established that, for the Mg2B2O5–Al system, the highest quantity of MgAl2O4 is observed at a pressure of 2GPa and a temperature of 1600°C. A further increase in temperature and pressure leads to a growth in the content of boron-containing phases. For the MgO–Al2O3 and MgO–Al2O3–Al systems, as well as for the Mg2B2O5–Al system, the MgAl2O4 phase content is observed to decrease with an increase in the compaction pressure. It’s indicate that an increase in pressure suppresses the interaction between the initial components for all the systems. The addition of aluminum as a liquid-phase component makes it possible to extend the pressure range, within which the MgAl2O4 phase is observed to form, to evidence that this approach to MgAl2O4 synthesis is promising for further application.