ChemInform Abstract: Syntheses, Structural Analyses, and Unusual Magnetic Properties of Ba2CoSi2O7 and BaCo2Si2O7

1996

structure

structure (solids and liquids) D 2000 Syntheses, Structural Analyses, and Unusual Magnetic Properties of — The title compounds are obtained 38 - 007 Ba2CoSi2O7 and BaCo2Si2O7. from stoichiometric mixtures of BaCO3, CoCO3, and SiO2 (1300 ◦ C, 48 h; Pt crucible, air). The structures of both compounds are determined by single crystal XRD. Ba2CoSi2O7 (I) crystallizes in the monoclinic space group C2/c with Z = 4. BaCo2Si2O7 (II) also belongs to space group C2/c (Z = 8). The Co atoms in (I) and (II) are tetrahedrally surrounded by four O atoms of the (Si2O7)6- groups. In (I) the cobalt ions are isolated while the CoO4 tetrahedra in (II) are linked via corner-sharing to form chains. Both compounds exhibit Curie-Weiss behavior consistent with tetrahedral Co(II) ions. (II) undergoes a transition at 21 K to a state having a field-induced weak ferromagnetic response. — (ADAMS, R. D.; LAYLAND, R.; PAYEN, C.; DATTA, T.; Inorg. Chem. 35 (1996) 12, 3492-3497; Dep. Chem. Biochem., Univ. S. C., Columbia, SC 29208, USA; EN)

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