The synthesis and characterization of vanadium difluoride, NaVF₃, KVF₃, and RbVF₃

The divalent vanadium compounds, NaVF3, KVF3, and RbVF3, have been prepared. They have the cubic perovskite structure with lattice constants of 3.94, 4.10, and 4.17 Å respectively. Magnetic susceptibility measurements showed large negative paramagnetic Curie temperatures, but no evidence of long-range antiferromagnetic order. The conditions under which pure VF2 can be prepared have also been studied and a diagram showing the relationship between temperature, hydrogen-hydrogen fluoride ratio, and the phases formed in the V-F system has been constructed. Single crystals of VF2 have been grown and characterized magnetically and optically. © 1969.