Sol-gel synthesis of triclinic CoV2O6 polycrystals

In this paper, a new chemical route synthesis for γ-CoV2O6 is proposed. Based on the CoO-V2O5 phase diagram a study of temperature and calcination times for pure γ-CoV2O6 obtainment is described. X-ray diffraction and Raman spectroscopy experiments revealed the triclinic crystals structure belonging to P-1 spatial group. FEG-SEM images showed that the resulting grains present elongated shape. Rietveld analysis revealed a crystalline anisotropy with preferential crystallographic orientation in the [2 0 − 1] and [1 3 0] planes. The calculated mean crystallite size evidences that the crystallite dimensions are significantly different in the parallel and perpendicular directions. The magnetic properties measurements evidenced an antiferromagnetic transition at 7 K and a detailed view of the magnetization isotherms confirmed a noticeable step-like behavior below TN, characteristic of field-induced transitions.