NMR data on ${}_{}{}^{17}{}_{}{}^{}\mathrm{O}$ and ${}_{}{}^{63}{}_{}{}^{}\mathrm{Cu}$ in ${\mathrm{La}}_{1.85}$${\mathrm{Sr}}_{\mathit{x}}$${\mathrm{CuO}}_4$ are presented and agree well with published work. Relaxation curves for ${}_{}{}^{63}{}_{}{}^{}\mathrm{Cu}$ and for both apical and planar ${}_{}{}^{17}{}_{}{}^{}\mathrm{O}$ sites are compared with calculations based on parametrization of recent absolute neutron susceptibilities χ’’(q,ω). A reasonable accord is found with the ${}_{}{}^{63}{}_{}{}^{}\mathrm{Cu}$ data. However, a significant discrepancy with the observed planar ${}_{}{}^{17}{}_{}{}^{}\mathrm{O}$ relaxation behavior poses an apparent contradiction with the widely accepted one-band dynamical model for this system.

• Received 14 October 1993

DOI:https://doi.org/10.1103/PhysRevLett.72.3610