EPR study of defect centers in Zn2InV3O11

A multicomponent vanadate compound Zn 2 InV 3 O 11 has been synthesized and investigated using the electron paramagnetic resonance (EPR) technique. The Zn 2 InV 3 O 11 compound is isostructural with a previously studied magnetic system M 2 FeV 3 O 11 (M = Mg, Zn, Co, Ni). According to the nominal stoichiometry of the Zn 2 InV 3 O 11 compound all ions are non-magnetic, but the registered EPR spectra in the 4-300 K temperature range have revealed the presence of a rich variety of paramagnetic centers involving predominantly monomeric and dimeric units, as well as clusters of V 4+ ions. The most intense EPR component, attributed to the VO 2+ vanadyl ion in an axial symmetry, has displayed a well resolved hyperfine structure. The presence of a complicated spectrum at low magnetic field (g 4.4) and a broad line at g 2 has confirmed the existence of vanadium dimers. A spectral feature attributed to vanadyl spin clusters has been observed at temperatures above 80 K in the 270-310 mT magnetic field range. The role of oxygen deficiency in the appearance of the observed magnetic centers has been discussed. Comparison with the previously studied Mg 2 ΙnV 3 O 11-δ compound has been made and the influence of specific cations on magnetic defect centers has been considered.