A Chromium−Vanadyl Ferrimagnetic Molecule-Based Magnet: Structure, Magnetism, and Orbital Interpretation
journal contributionposted on 08.01.1999, 00:00 by S. Ferlay, T. Mallah, R. Ouahès, P. Veillet, M. Verdaguer
The synthesis, structural characterization, and magnetic properties of a new Prussian blue analogue, the molecule-based ferrimagnet (VIVO)[CrIII(CN)6]2/3·10/3H2O (1) (TC = 115 K), are presented. The crystal structure is determined from the powder X-ray diffraction diagram using the Rietveld method. The system is cubic, space group Fm3m with cell parameter a = 10.490(4) Å. The value of the exchange coupling parameter J (−48 cm-1) between CrIII and VIVO is estimated from the molecular field parameter W, obtained by fitting the |χM-1| = f(T) data in the paramagnetic phase of the compound. The dependence of the TC value is analyzed in relation with the connectivity of the molecular precursor, the stoichiometry of the three-dimensional material, and the nature of the constituting metal ions. The TC value of 1 is compared to that of the high-TC ferrimagnet (315 K) V[Cr(CN)6]0.86·2.8H2O (2); the values of the J parameters are almost the same. This allows us to estimate the TC values for other possible vanadium−chromium ferrimagnets.