NMR study of magnetic moments arising in superconducting cuprates under electron/neutron irradiation

The measurements of direct-current magnetic susceptibility and nuclear magnetic resonance (NMR) were performed in the superconducting cuprates YBa₂Cu₃O_6.9 (⁸⁹Y,⁶³Cu), Tl₂Ba₂CaCu₂O₈ (¹⁷O,²⁰⁵Tl), irradiated by fast neutrons (E _n = 1 MeV) and electrons (E _e = 5 MeV). The influence of the radiation-induced structural disorder on the spin susceptibility and magnetic state of atoms in the CuO₂ layer is considered. The possible effect onT _c of the spin-exchange scattering of carriers by localized moments arising under irradiation was estimated following the Abrikosov-Gorkov approach and its contribution was found to be too small in comparison with the real suppression ofT _c under irradiation.