NMR Evidence of Antiferromagnetic Spin Fluctuations in Nd_0.85Sr_0.15NiO₂

Despite the recent discovery of superconductivity in Nd$_{1-x}$Sr$_{x}$NiO$_2$ thin films, absence and antiferromagnetism their bulk materials remain a puzzle. Here we report $^{1}$H NMR measurements on powdered Nd$_{0.85}$Sr$_{0.15}$NiO$_2$ samples by taking advantage enriched proton concentration after hydrogen annealing. We find large full width at half maximum spectrum, which keeps increasing with decreasing temperature exhibits an upturn behavior low temperatures. The spin-lattice relaxation rate $1/^{1}T_1$ is strongly enhanced when lowering temperature, developing broad peak about 40 K, then decreases following spin-wave-like $1/^{1}T_1{\sim}T^2$ lower These results evidence short-range glassy antiferromagnetic ordering magnetic moments below K dominant fluctuations extending to much higher Our findings reveal strong electron correlations Nd$_{0.85}$Sr$_{0.15}$NiO$_2$, shed light mechanism observed films nickelates.