Synchrotron X-ray diffraction study of a charge stripe order in 1/8-doped La$_{1.875}$Ba$_{0.125-x}$Sr$_{x}$CuO$_{4}$

摘要

Lattice distortions associated with charge stripe order in 1/8 hole-dopedLa$_{1.875}$Ba$_{0.125-x}$Sr$_{x}$CuO$_{4}$ are studied using synchrotron X-raydiffraction for $x=0.05$ and $x=0.075$. The propagation wave vector and chargeorder correlation lengths are determined with a high accuracy, revealing thatthe oblique charge stripes in orthorhombic $x=0.075$ crystal are moredisordered than the aligned stripes in tetragonal $x=0.05$ crystal. The twofoldperiodicity of lattice modulations along the c-axis is explained by long-rangeCoulomb interactions between holes on neighboring CuO$_{2}$ planes.