Influence of hydrogen on theY89NMR inHxYBa2Cu3O7

The ambient-temperature ${}_{}{}^{89}{}_{}{}^{}\mathrm{Y}$ magnetic resonance line in ${\mathrm{H}}_{\mathit{x}}$ ${\mathrm{YBa}}_2$ ${\mathrm{Cu}}_3$ ${\mathrm{O}}_7$ was measured at 14.707 MHz as a function of hydrogen concentration x. The Knight shift relative to an aqueous solution of ${\mathrm{YCl}}_3$ increases from -100 ppm for x=0 to +115 ppm for x=1.82. The linewidth at half-amplitude is 1.2 kHz and increases slowly with x in the superconducting samples (0<x<0.74), then increases sharply in the normal samples. It was seen that, for a number of parameters, increasing the hydrogen content gives similar behavior to decreasing the oxygen concentration. Our ${}_{}{}^{89}{}_{}{}^{}\mathrm{Y}$ NMR data and those of other investigators are analyzed and are consistent with previous evidence for local antiferromagnetic correlations in the superconducting compound.