Structural properties and Raman spectra of columbite-type NiNb2−V O6 synthesized under high pressure

J.P. Pena (1, 2) , Pierre Bouvier (1) , O. Isnard (1)

1 NEEL - MRS - Matériaux, Rayonnements, Structure
2 UFRN - Universidade Federal do Rio Grande do Norte [Natal]

The complete set of structural parameters of the new series of compounds NiNb 2−x V x O 6 (0 ≤ x ≤ 2) with the columbite-type structure is presented here. In the samples containing vanadium, this crystalline structure was stabilized by synthesis in conditions of high pressure and high temperature. The evolution of the vibrational Raman spectrum produced when the vanadium is substituted for niobium along the series is also presented and discussed. This evolution is interpreted by taking into account the changes in the local structural environment of the niobium/vanadium atoms and its influence over the nickel-oxygen bonds around them. The presence of vanadium atoms favors an increasing of the symmetry in the arrangement of oxygen atoms around the nickel-ones; in counterpart the vanadium is in an octahedral environment which is more distorted than that of the niobium. Because of these apparently subtle differences, the homogeneous percolation of vanadium in the solid solution NiNb 2−x V x O 6 is not possible.

Domaines: Chimie inorganique; Matériaux; Science des matériaux [cond-mat.mtrl-sci]

J.P. Pena, Pierre Bouvier, O. Isnard. Structural properties and Raman spectra of columbite-type NiNb2−V O6 synthesized under high pressure. Journal of Solid State Chemistry, 2020, 291, pp.121607. ⟨10.1016/j.jssc.2020.121607⟩. ⟨hal-02921507⟩