Unveiling the electronic origin of anion order in CrO2−xFx

Abstract

Electron-diffraction and high-resolution lattice images reveal superstructure stripes with wave vectors of (1/3, 0, 1/3) and (−1/3, 0, 1/3), which are associated with the ordered arrangement of F⁻. Charge density distribution suggests that these stripes manifest themselves electronically as F⁻–Cr³⁺–F⁻ zigzag chains, driven by the anisotropic charge interaction of F⁻ anions.