Synchrotron X-ray diffraction study of a charge stripe order in 1/8-doped La${}_{1.875}$Ba${}_{0.125-x}$Sr${}_x$CuO${}_4$

Abstract

Lattice distortions associated with charge stripe order in 1/8 hole-doped La${}_{1.875}$Ba${}_{0.125-x}$Sr${}_x$CuO${}_4$ are studied using synchrotron X-ray diffraction for $x=0.05$ and $x=0.075$. The propagation wave vector and charge order correlation lengths are determined with a high accuracy, revealing that the oblique charge stripes in orthorhombic $x=0.075$ crystal are more disordered than the aligned stripes in tetragonal $x=0.05$ crystal. The twofold periodicity of lattice modulations along the c-axis is explained by long-range Coulomb interactions between holes on neighboring CuO${}_2$ planes.

4pages, 4figures, Submitted to PRB