title: K2M(III)2(M(VI)O4)(PO4)2 (M(III) = Fe, Sc; M(VI) = Mo, W), novel members of the lagbeinite-related family: synthesis, structure, and magnetic properties.
abstract: The possibility of PO(4)(3-) for MoO(4)(2-) 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 1/3PO(4)(3-) for MoO(4)(2-) substitution leads to formation of three novel compounds K(2)Fe(MoO(4))(PO(4))(2), K(2)Sc(MoO(4))(PO(4))(2), and K(2)Sc(WO(4))(PO(4))(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.
authors.affiliation: Inorganic Chemistry Department, Kiev Taras Shevchenko University, Volodymyrska Street 64, Kiev 01601, Ukraine.
authors.forename: Nikolay S
authors.initials: NS
authors.lastname: Slobodyanik
authors.forename: Kateryna V
authors.initials: KV
authors.lastname: Terebilenko
authors.forename: Ivan V
authors.initials: IV
authors.lastname: Ogorodnyk
authors.forename: Igor V
authors.initials: IV
authors.lastname: Zatovsky
authors.forename: Maksym
authors.initials: M
authors.lastname: Seredyuk
authors.forename: Vyacheslav N
authors.initials: VN
authors.lastname: Baumer
authors.forename: Philipp
authors.initials: P
authors.lastname: Gütlich