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

Raman spectra of vanadates MV2O6 (M=Peña1, Bouvier2, Hneda3 et al. 2021Journal of Physics and Chemistry of SolidsSelf Cite10000View full textAdd to dashboardCite

“…With respect to the isostructural columbite-niobates, M Nb 2 O 6 , the mode A g (1) is observed at higher wavenumbers in those compounds than in the vanadates M V 2 O 6 when M =Mn [35], Co (own measure, not shown), and Ni [16].…”

“…We calculated the set of interatomic distances and distortion indexes ∆ reported in Table 3 and Zn are reported for the first time, while that for M =Ni is recalled from our previous work recently published in Ref. [16]. We can first observe in Fig.…”

“…The difficulty of interpreting the variation of the position of the A g (1) mode only with basis on the interatomic distances of the V-O t bond in the columbites M V 2 O 6 had also been evidenced in the analysis of the whole series of samples NiNb 2−x V x O 6 studied in Ref. [16]. There, it was concluded that the relative wavenumber of the highest intensity Raman peak is very sensitive to the specific details of the crystalline structure as a whole and apparently this mode tends to appear at lower wavenumbers in more symmetric structures.…”

“…When synthesised at room pressure these vanadates are found to adopt low symmetry structures such as triclinic P 1 for M =Cu, Ni or monoclinic C2/m for M =Mg, Mn, Cd and Zn [9,10]; when M =Co the structure can be triclinic or monoclinic depending on the temperature of synthesis [11,12,13]. By high pressure and temperature (HPHT) synthesis, some of these vanadates can be obtained in an orthorhombic structure with the Pbcn space group [14,15,16]; this is the columbite-type structure, typical of the room-pressure synthesised niobates (M B 2 O 6 , B =Nb). Previously, we reported the first Raman spectrum for the Pbcn NiV 2 O 6 [16], and here we report the Raman spectra of Pbcn MnV 2 O 6 , CoV 2 O 6 and ZnV 2 O 6 .…”

“…By high pressure and temperature (HPHT) synthesis, some of these vanadates can be obtained in an orthorhombic structure with the Pbcn space group [14,15,16]; this is the columbite-type structure, typical of the room-pressure synthesised niobates (M B 2 O 6 , B =Nb). Previously, we reported the first Raman spectrum for the Pbcn NiV 2 O 6 [16], and here we report the Raman spectra of Pbcn MnV 2 O 6 , CoV 2 O 6 and ZnV 2 O 6 . To the best of our knowledge, this is the first report on the Raman spectra of these compounds crystallised in this specific structure.…”