Spin Correlations and Magnetic Order in Nonsuperconducting ${\mathrm{N}\mathrm{d}}_{2-x}{\mathrm{C}\mathrm{e}}_x{\mathrm{C}\mathrm{u}\mathrm{O}}_{4\pm \delta }$

We report quantitative neutron scattering measurements of the evolution with doping of the Néel temperature, the antiferromagnetic correlations, and the ordered moment of as-grown, nonsuperconducting ${\mathrm{N}\mathrm{d}}_{2-x}{\mathrm{C}\mathrm{e}}_x{\mathrm{C}\mathrm{u}\mathrm{O}}_{4\pm \delta }$ ($0\le x\le 0.18$). The instantaneous correlation length can be effectively described by our quantum Monte Carlo calculations for the randomly site-diluted nearest-neighbor spin-$1/2$ square-lattice Heisenberg antiferromagnet. However, quantum fluctuations have a stronger effect on the ordered moment, which decreases more rapidly than for the quenched-disorder model.