Synthesis and X-ray powder diffraction data for MNbF_6 (M=Fe, Co) compounds

摘要

X-ray diffraction experiments performed on the compounds Fe~ⅡNb~ⅣF_6 and Co~ⅡNb~ⅣF_6 have shown that they crystallize in the rhombohedral system, space group R3 with a cationic ordering. Unit cell parameters were determined: a=5.4201(8)A, c=14.072(2)A, Z=3 for FeNbF_6, and a=5.351(2) A, c=13.960(6) A, V=346.2(2) A, Z=3 for CoNbF_6. Synthesis and powder diffraction data are reported.