Similarity of Slow Stripe Fluctuations between Sr-Doped Cuprates and Oxygen-Doped Nickelates

Stripe fluctuations in ${\mathrm{La}}_2{\mathrm{NiO}}_{4.17}$ have been studied by ${}^{139}\mathrm{La}$ NMR using the field and temperature dependence of the linewidth and relaxation rates. In the formation process of the stripes, the NMR line intensity is maximal below 230 K, starts to diminish around 140 K, disappears around 50 K, and recovers at 4 K. These results are shown to be consistent with, but completely complementary to, neutron measurements, and to be generic for oxygen-doped nickelates and underdoped cuprates.