Magnetic study of Cr3+ ion in M2CrV3O11−x (M6-point double bond; length half of m-dashZn, Mg) compounds

Electron paramagnetic resonance (EPR) and magnetic susceptibility measurements on the recently synthesized vanadates M2CrV3O11−x (M=Zn, Mg) have been analyzed. Two absorption lines with g≈2.0 (type I) and image (type II) were recorded in the EPR spectra, which can be attributed to V4+ ions and Cr3+ ion clusters (pairs), respectively. The exchange constant J between Cr3+ ions has been calculated, using both EPR and magnetic susceptibility data. Fitting of the EPR and magnetic susceptibility data has been carried out. The sign of J is a negative one for all samples and indicates antiferromagnetic interactions. Some difference in the J constant value among samples has been obtained. Volumetric titration confirms distinctly the presence of vanadium V4+ ions in the investigated compounds.