Modification of structure and charge states of defects in corundum crystals under X radiation

Investigation of Al2O3 single crycstals subjected to different methods of thermochemical treatment promotes identification of several genetically linked hole centres: isolated V- and Vsup(=) centres with thermal destruction at 377 and 470 K, Vsub(M)sup(-) and Vsub(M)sup(=) centres located near impurity ions Me3+ with destruction temperatures 400 and 530 K, respectively. Existence of charge-compensated cation vacancies Vsub(c)sup(3-)Hsup(+) is suggested transformed into Vsub(OH)sup(-) centres when the hole is captured by irradiation. The trapping of the second hole leads to dissociation of Vsub(OH)sup(0) centres into V- centres and interstitial ions Hsub(i)sup(+). Cation defects with two ions H+ under irradiation are transformed into Vsub(OH)sup(-) centres and Hsub(i)sup(+)