Effect of mechanoactivation on the phase transitions in the oxide systems

Abstract

Abstract In the paper, the influence of mechanoactivation on the high-temperature behavior of systems with metastable phases is analyzed. Comparison of structural phase transformations in the conditions of temperature growth in various oxides subjected to mechanochemical activation and structural characteristics of the resulting crystalline phases allows us to estimate whether the previously established regularities are common for systems with different types of chemical bond. The influence of mechanical activation on structural phase transitions of both the martensitic type (for example, from the cubic into the tetragonal modification in Mn3O4) and accompanied by redox processes (between phases with different oxidation degrees, etc.) is considered. It is shown despite the relaxation character of the evolution of the metastable structures obtained the temperature shift of the corresponding phase transitions takes place together with changes in the structural characteristics of the newly formed phases in comparison with the initial oxides.