Jason D. Pless

Crystal growth and co-substitution in (Mg1-xFex)(Mo2-xVx)O7 (0.13≤x≤0.47) with (V/Mo)=O oxo double bonds

Abstract New solid solution crystals of (Mg 1− x Fe x )(Mo 2− x V x )O 7 (0.13≤ x ≤0.47) were grown from MgO–Fe 2 O 3 –V 2 O 5 –MoO 3 melts. Single crystal X-ray diffraction studies reveal that the structure consists of (Mg/Fe) 2 O 10 octahedral dimers and [(Mo 2− x V x )O 7 ] (2+ x )− tetrahedral clusters. The structure contains (V/Mo)ue605O oxo double bonds similar to MgMo 2 O 7 and FeVMoO 7 . Equimolar co-substitution of V 5+ for Mo 6+ and Fe 3+ for Mg 2+ avoids the creation of any ion vacancies or interstitials and generates disordered cation sites. Crystal data: for (Mg 0.87 Fe 0.13 )(Mo 1.87 V 0.13 )O 7 , monoclinic, space group P 2 1 / n (No. 14), with a =8.3356(6) A, b =9.1079(6) A, c =8.5086(6) A, β =111.927(1)° and Z =4; for (Mg 0.53 Fe 0.47 )(Mo 1.53 V 0.47 )O 7 , monoclinic, space group P 2 1 / n (No. 14), with a =8.2766(6) A, b =9.0208(7) A, c =8.4817(6) A, β =112.144(1)° and Z =4.