Evidence for Short-Range-Ordered Charge Stripes Far above the Charge-Ordering Transition inLa1.67Sr0.33NiO4

A. M. Milinda Abeykoon, Emil S. Božin, Wei-Guo Yin, Genda Gu, John P. Hill, John M. Tranquada, Simon J. L. Billinge
2013 Physical Review Letters  
The temperature evolution of structural effects associated with charge (CO) and spin order (SO) in La_1.67Sr_0.33NiO_4 has been investigated using neutron powder diffraction. We report an anomalous shrinking of the c/a lattice parameter ratio that correlates with T_ CO. The sign of this change can be explained by the change in interlayer Coulomb energy between the static stripe-ordered state and the fluctuating stripe-ordered state or the charge-disordered state. In addition, we identify a
more » ... ibution to the mean-square displacements of Ni and in-plane O atoms whose width correlates quite well with the size of the pseudogap extracted from the reported optical conductivity, with a non-Debye-like component that persists below and well above T_ CO. We infer that dynamic charge-stripe correlations survive to T∼2T_ CO
doi:10.1103/physrevlett.111.096404 pmid:24033056 fatcat:fxwju54ybfgltcrjbfpnmczrx4