FORMATION OF RADICAL FORMS OF ADSORBED OXYGEN IN ILLUMINATION OF CALCIUM-OXIDE IN THE REGION OF SURFACE-ABSORPTION

The mechanism of photoprocesses taking place in the region of surface absorption of calcium oxide (hnu less-than-or-equal-to 4 eV) and accom panied by the formation of radical forms of adsorbed oxygen on its sur face was investigated. The formation of oxygen radical anions O2- and complexes of molecular oxygen with hole centers [X.O2](g1 = 2.002; g2 = 2.009; g3(1) = 2.015; g3(2) = 2.016) and [Y.O2] (g(parallel-to) = 2. 004; g(perpendicular-to) = 2.012) as a result of photoadsorption was d etected. The ESR spectra of the X and Y centers are not observed in th e 90-300 K range. It was hypothesized that they are O(st)- radical ani ons in different coordination: (O3c-)st and (O4c-)st, respectively.