PVDF fluorination of La4Co3O10: Synthesis, structure and physical properties of La4Co3O10F2

Abstract

Topochemical fluorination of oxides recently gained interest as it opens the way to substantial structural modifications and drastic changes in physical properties. We present a study of La₄Co₃O₁₀F₂, synthesized via low-temperature topochemical methods using polyvinylidene difluoride (PVDF). Using synchrotron X-ray powder diffraction, we find the compound to crystallize in a monoclinic cell (A2/a, with a = 5.32969(9) Å, b = 5.37555(1) Å, c = 30.5958(6) Å and β = 90.994(1) °), where the fluoride anions occupy the rock-salt layer's interstitial sites, inducing a tilting of the CoO₆ octahedra. The physical properties of this novel compound are compared with those of the parent compound La₄Co₃O₁₀, evidencing changes in resistivity and magnetism, highlighting the possibility of tuning magnetic interactions and electronic correlations through PVDF fluorination.