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

TL;DR

This study uses synchrotron X-ray diffraction to analyze charge stripe order and lattice distortions in 1/8-doped La-based cuprates, revealing differences in stripe disorder and the role of Coulomb interactions.

Contribution

It provides detailed measurements of charge stripe propagation vectors and correlation lengths in La$_{1.875}$Ba$_{0.125-x}$Sr$_{x}$CuO$_{4}$, highlighting the impact of crystal structure on stripe disorder.

Findings

Oblique charge stripes are more disordered in orthorhombic crystals.

Aligned stripes are more ordered in tetragonal crystals.

Long-range Coulomb interactions explain lattice modulation periodicity.

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.