VARIATIONS IN THE YBA2CU3O6,9 ELECTRON SP ECTRUM WITH RADIATIVE DISORDERING - NMR Y-89 AND CU-63 DATA

In YBa1Cu3O6,9 compound exposed by radiative disordering with fast neu trons of flux phi = 0 - 5.10(19) cm-2 the components of shift Y-89 and Cu-63 NMR tensor and the nuclear Y69 spin-lattice relaxation rate are measured in order to obtain the estimates for changing the spin contr ibution chi(s)(q = 0) into the magnetic susceptibility during producin g the structural disorder. The results obtained demonstrate a drastic reduction of the density of states near the Fermi energy, resulting in the formation of the Coulomb gap at the Fermi level for nonsupercondu cting samples. NMR Y-89 data give an evidence for the appearance of an antiferromagnetic order among localized magnetic moments arising in C uO2 planes with irradiation at low temperatures.. The features of nucl ear 69Y, spin-lattice relaxation in the region of metallic conduction arv discussed exhibiting the metal-insulator Anderson transition in th e system concerned and verifying the corresponding theoretical conside rations.