NMR Study ofO17Transverse Relaxation inYBa2Cu3(16O1−c17Oc)7

Abstract

NMR transverse relaxation (TR) measurements of ${}^{17}\mathrm{O}(2,3)$ in ${\mathrm{YBa}}_2{\mathrm{Cu}}_3{(}^{16}{\mathrm{O}}_{1-c}^{17}{\mathrm{O}}_c{)}_7$ are presented. A Gaussian-like relaxation is found. The origin of this relaxation is investigated by varying $c$, the temperature, the external field, and by comparing it with the ${}^{17}\mathrm{O}\left(4\right)$ site. Our results are consistent with a model in which this relaxation is caused by the dynamical fluctuation of copper nuclei, including both spin-lattice and flip-flop processes. With this model we can also explain the TR of ${}^{89}\mathrm{Y}$ and ${}^{63}\mathrm{Cu}\left(1\right)$. We use our results to reanalyze previous NMR ${}^{63}\mathrm{Cu}\left(2\right)$ TR data and find the dynamical exponent $z=1\mathrm{}$.