Search for structural fluctuations in the disordered stripe state of Nd$_{1:67}$Sr$_{0:33}$NiO$_{4}$

We present a temperature series PDF and a Rietveld analysis of Nd$_{1:67}$Sr$_{0:33}$NiO$_{4}$ system to study the local structural response in the state above the charge-ordered state that has not been characterized in detail to date. We observed NiO$_{6}$ octahedral tilting patterns of different magnitude for short and long-range structure of the system. A sequential Rietveld refinement, and a T-series PDF analysis on the length scale (5-20){\AA} were carried out to characterize the long-range order of the system. A PDF analysis on the length scale (0-4.2) {\AA} revealed a different magnitude local octahedral tilt pattern as a function of temperature. The correlation length of short-range ordered charge stripes existing above T$_{co}$ was estimated using a Box-Car type PDF model. Combining this information with the refined isothermal atomic displacement parameters (ADPs) yields a much more complete picture of the nature of both atomic displacements and how they are correlated with each other in the system.