STABILIZATION OF ELEMENTS IN UNUSUAL OXIDATION-STATES AND TEMPERATURE-REVERSIBLE DYNAMICS OF ELECTRON PAIRS IN OXIDE GLASSES - EPR-INVESTIGATION

Binary, three-component and multi-component berate, phosphate, germana te and silicate glasses, as well as barium-aluminophosphate glasses co ntaining oxide of metals of(I-V)B groups, metals of the first transiti on series from titanium to nickel, niobium, tantalum, molybdenum and t ungsten are investigated by EPR and optical spectroscopy at 77 and 300 K. The formation of metal ions in unusual oxidation states, such as A g-0, Zn1+, Cd1+, Hg1+, Ga2+, Tl2+, Ge3+, Sn3+, Pb3+, Sb4+, Bi4+, Nb4+, Ti3+, Ni1+, Mo5+, Cr3+, and Cr5+ was established. They were stabilize d in the aforementioned glasses at specific compositions of components for an unlimited time at 300 K. It is shown that the reversible low t emperature effect of disproportionation on atoms such as Nb, Ti, V, Mo , and W proves that in glass under ionizing gamma-radiation and temper ature the reactions of disproportionation occur together with the reco nstruction of conformation, the electron density transfer, the atomic displacement and the change (reversible or not) of a local structure o f glass. It is shown that the formation of metal clusters in glass is connected with reaction of disproportionation.