A CHEMICAL STATE OF THE SURFACE OF MECHANOACTIVATED MANGANESE (MnmOn) OXIDES
<i>A surface of manganese oxides: Mn</i><sub><i>3</i></sub><i>O</i><sub><i>4</i></sub><i>, Mn</i><sub><i>2</i></sub><i>O</i><sub><i>3</i></sub><i>, and MnO</i><sub><i>2</i></sub><i>, mechanoactivated by a high intensity grinding technology has been studied by X-ray photoelectron spectroscopy. Mn</i><sub><i>2</i></sub><i>O</i><sub><i>3</i></sub><i> has been found to be the most thermodynamically stable of all the oxides under investigation. The surface layer of the Mn</i><sub><i>3</i></sub><i>O</i><sub><i>4</i></sub><i> and MnO</i><sub><i>2</i></sub><i> oxides due to the mechanoactivation has transformed into a stable Mn</i><sub><i>2</i></sub><i>O</i><sub><i>3</i></sub><i> form. Furthermore, the process of mechanoactivation has substantially enhanced a chemical stability of Mn</i><sub><i>2</i></sub><i>O</i><sub><i>3</i></sub><i> against environmental impacts. The obtained results have been explained in terms of specific features of the activated surface structural condition.</i>