Using high-resolution x-ray scattering, we have demonstrated the existence of quenched disordered charge stripes in a single crystal of $\mathrm{La}{}_{5/3}\mathrm{Sr}{}_{1/3}\mathrm{NiO}{}_4$ at low temperatures. Above the second-order transition critical scattering was observed due to fluctuations into the charge stripe phase. The charge stripes are shown to be two dimensional in nature both by measurements of their correlation lengths $({\xi }_a\approx 185Å$, ${\xi }_b=400Å$, and ${\xi }_c\approx 25Å$) and by the critical exponents of the charge strip transition. The charge stripe ordering did not develop long-range order even at low temperatures, indicating that the charge stripes are disordered and that the length scale of the disorder is quenched.

• Received 19 April 1999

DOI:https://doi.org/10.1103/PhysRevLett.84.3911