Nanoscale anisotropic structural correlations in the paramagnetic and ferromagnetic phases of Nd0.5Sr0.5MnO3 - art. no. 144406

We report x-ray scattering studies of short-range structural correlations a nd diffuse scattering in Nd0.5Sr0.5MnO3. On cooling, this material undergoe s a series of transitions, first from a paramagnetic insulating (PI) to a f erromagnetic metallic (FM) phase, and then to a charge-ordered (CO) insulat ing state. Highly anisotropic structural correlations were found in both th e PI and FM states of this compound. The correlations increase with decreas ing temperature, reaching a maximum at the CO transition temperature. Below this temperature, they abruptly collapsed. Single-polaron diffuse scatteri ng was also observed in both the PI and FM states suggesting that substanti al local lattice distortions are present in these phases. We argue that our measurements indicate that nanoscale regions exhibiting layered orbital or der exist in the paramagnetic and ferromagnetic phases of Nd0.5Sr0.5MnO3.