ISSN:
1090-6487
Keywords:
61.80.Hg
;
76.60.Es
;
74.72.Bk
;
74.25.Nf
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract The spin-spin relaxation rate 63 T 2 −1 of 63Cu nuclei in CuO2 layers is measured in the normal and superconducting states of the compound YBa2Cu3O6.9 (T c onset =94 K) subjected to radiation-induced disordering by a fast-neutron flux Φ to T c onset =68 K (Φ=7×1018 cm−2) and T c onset 〈4 K (Φ=12×1018 cm−2). It is found that as the structural disorder increases, the contribution of the indirect spin-spin interaction 63 T 2G −1 , which is related to the value of the spin susceptibility at the boundary of the Brillouin zone of the copper planes χs(q={π/a; π/a}), decreases slightly at the transition to the superconducting state for the initial sample and remains unchanged for the weakly disordered sample. This behavior of the short-wavelength contribution to the spin susceptibility attests to the stability of the x 2−y 2 symmetry of the energy gap against structural disorder, in accordance with proposed theoretical models of Cooper pairing for high-T c cuprates.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1134/1.567648
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