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Updated: May 17, 2026

Molten-Salt Synthesis of Complex Metal Oxide Nanoparticles
Published on: October 27, 2018
K2CaV2O7: a pyrovanadate with a new layered type of structure in the A2BV2O7 family
Alexander P Tyutyunnik1, Boris V Slobodin, Rina F Samigullina
1Institute of Solid State Chemistry, Ural Branch of the Russian Academy of Sciences, 91 Pervomayskaya str., Ekaterinburg GSP-145, 620990, Russia.
Abstract:
The crystal structure of K(2)CaV(2)O(7) prepared by a conventional solid-state reaction has been solved by a direct method and refined using Rietveld full profile fitting based on X-ray powder diffraction data. This compound crystallises in the triclinic space group (P1, Z = 2) with unit cell constants a = 7.1577(1) Å, b = 10.5104(2) Å, c = 5.8187(1) Å, α = 106.3368(9)°, β = 106.235(1)°, γ = 71.1375(9)°. The structure can be described as infinite undulating CaV(2)O(7)(2-) layers parallel to the ac plane, which consist of pairs of edge-sharing CaO(6) octahedra connected to each other through V(2)O(7) pyrogroups. The potassium atoms are positioned in two sites between the layers, with a distorted IX-fold coordination of oxygen atoms. The chemical composition obtained from the structural solution was confirmed by energy-dispersive X-ray analysis. The stability of compounds in the family of alkali metal calcium pyrovanadates is discussed based on an analysis of the correlation between anion and cation sizes and theoretical first-principles calculations.
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