Magnetic-flux-lattice anisotropy ofTl2Ba2Ca2Cu3O10+δbyTl205nuclear magnetic resonance

Abstract
Tl205 nuclear-magnetic-resonance spectra of aligned powders of Tl2 Ba2 Ca2 Cu3 O10+δ were measured at 5 K as a function of the angle between the magnetic field and the alignment axis. Using the alignment distribution obtained from an analysis of normal-state spectra, spectra for perfectly aligned crystals were extracted. The angular dependence of the resonance-frequency shift was found to be consistent with the anisotropic London theory, and the average penetration depth was found to be 7040 Å. A small reduction of the spin shift at 5 K was observed.