“…The typical result of this material . Thus optical spectroscopy [3][4][5][6], procedure is a tongue-shaped blackened region in the EPR measurements [6][7][8][9][10][11][12][13][14][15][16][17][18], conductivity measurecenter of the specimen since the surfaces of the ments [1,6,19,20], electron microscopy [21], X-ray specimen can still act as oxygen sources. Essentially, studies [7], dielectric measurements [22] and meathe activity of oxygen in the reduced material is surements of elastic properties [23,24] were percontrolled kinetically rather than thermodynamically.…”