RESUMO
In the course of an investigation to prepare the hypothetic new double perovskite La(3)Co(2)VO(9) with Co(2+) and V(5+) in octahedral sites, we obtained the new simple perovskite LaCo(0.71(1))V(0.29(1))O(2.97(3)) as the main phase. The pure compound was then synthesized by the citrate decomposition method. The crystal structure was studied by X-ray (PXRD) and powder neutron diffraction (PND). Physical properties were characterized by X-ray absorption spectroscopy (XAS), X-ray emission spectroscopy (XES) and thermogravimetric analysis (TGA). Rietveld refinements were performed in the orthorhombic space group Pnma (#62). Refined cell parameters were a = 5.4762(2) Å, b = 7.7609(2) Å and c = 5.5122(1) Å. Magnetization measurements showed that this perovskite is an antiferromagnet with a Neel temperature of 15 K. At high T the magnetization follows the Curie-Weiss law corrected by temperature independent paramagnetism (TIP) showing an effective magnetic moment of 3.03µ(B) well described by the contribution of Co(2+) (HS), Co(3+) (IS), V(3+) and V(4+) ions. The crystallographic formula was refined by PND and oxidation state distribution was determined by the combination of PND, XAS, TGA and magnetic measurements.
