Synthesis and crystallographic studies of garnet-type AgCa2Co2V3O12 and AgCa2Ni2V3O12

Vanadium compounds AgCa2Co2V3O12 and AgCa2Ni2V3O12 have been successfully synthesized by solid-state chemical reaction. The X-ray powder diffraction measurements verify that these compounds have the garnet-type structure with the lattice constant of 12.470(2) Å for AgCa2Co2V3O12 and 12.410(2) Å for AgCa2Ni2V3O12. The Rietveld refinements from X-ray powder diffraction data have been made. Our new results are compared with that obtained by the previous workers. Furthermore, the detailed crystallographic parameters are determined, which are tabulated and a short description is given for the experimental procedure.