Synthesis, crystal structure, and Raman spectra of mixed oxides K2Pb(MoO4)2–x (CrO4) x and K2 – x Pb1 + x (MoO4)(CrO4)1 – x (VO4) x , where x = 0–1

Abstract

Specimens of K2Pb(MoO4)2–x(CrO4)x and K2–xPb1 + x(MoO4)(CrO4)1–x(VO4)x (x = 0–1) solid solutions, which crystallize in palmierite structural type with space group R3m, were prepared by a citrate method. Position 3a that has octahedral configuration of oxygen atoms in K2Pb(MoO4)2–x (CrO4)x is occupied mainly by lead atoms, the share of potassium in this position is not larger 0.056–0.060(2). The introduction of vanadium cations in K2Pb(MoO4)2–x(CrO4)x crystal lattice leads to the complete displacement of potassium cations from MO6 coordination polyhedron and decrease of Pb–O6 distances from 2.679(5) to 2.665(4) A. Interactomic distances in (Pb/K)O6, (K/P)O10, and (Mo/Cr/V)O4 coordination polyhedra were calculated.