89Y NMR and Cu NQR of hydrogenated oxygen-deficient YBa2Cu3O6.7.

Abstract

The room-temperature $^{89}\mathrm{Y}$ NMR line shift and line shape as well as the low-temperature Cu NQR lines were obtained as a function of hydrogen concentration for oxygen-depleted hydrogen-doped YBCO (${\mathrm{H}}_{\mathit{x}}$${\mathrm{YBa}}_{2}$${\mathrm{Cu}}_{3}$${\mathrm{O}}_{6.7}$) in order to investigate the interplay of the effect of hydrogen addition and oxygen removal on the electronic structure and superconducting-antiferromagnetic transition properties. The results seem to indicate that as far as filling the conduction band is concerned, hydrogen contributes twice as many electrons as the chain oxygen contributes holes. In contrast to this, the transition from a superconductor to an antiferromagnet is governed by other considerations which favor a 1:1 ratio. It is also seen that hydrogen enters into either an additional site or a new phase when enough hydrogen is added to oxygen-depleted YBCO.