Temperature Dependence of the Magnetic Excitation Spectra of YBa2Cu2.9Zn0.1O6.75

Abstract
Neutron scattering measurements of magnetic excitations in YBa 2 Cu 2.9 Zn 0.1 O 6.75 (T c ≤10 K) have been performed. In contrast to the corresponding pure sample with the same oxygen number ( T c ≃66 K) where no peak of the antiferromagnetic correlation was detected for excitation energies below 15 meV, we have observed clear scattering contribution in the same energy range at all temperatures studied. A detailed study of χ ′′ (ω) at (π, π) in this Zn-substituted sample suggests 1) an existence of the gap-like structure at high temperatures (100 K< T T <50 K).