Search

The possibility of PO43- for MoO42- partial substitution in the langbeinite framework has been studied by exploration of the K-Fe(Sc)-Mo(W)-P-O systems using the high-temperature solution method. It was shown that 1/3PO43- for MoO42- substitution leads to formation of three novel compounds K2Fe(MoO4)(PO4)2, K2Sc(MoO4)(PO4)2, and K2Sc(WO4)(PO4)2 with slightly increased lattice parameters and significant distortion of the anion tetrahedra without structure changes. In contrast, the antiferromagnetic structure is modified by substitution in the low-temperature region. The structural peculiarities are discussed in light of bond-valence sums calculations. [ABSTRACT FROM AUTHOR]