S. Mao, Ya-Xi Huang, Zan‐Bin Wei
Feb 1, 2000
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0
Influential Citations
7
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Journal
IEEE Journal of Solid-state Circuits
Abstract
Abstract A sodium cobalt hydrogen phosphate hydrate, Na 4 Co 3 H 2 (PO 4 ) 4 ·8H 2 O, was synthesized by the mild hydrothermal method, and the crystal structure was characterized by the single-crystal X-ray diffraction method. The layered structure possesses a new type with the following data: Mr=794.775, monoclinic, mP 106, P 2 1 / c – e 26 d (No. 14), a =7.3547(9) A, b =9.222(1) A, c =15.186(2) A, β =95.18(1)°, V =1025.9(3) A 3 , Z =2, Dx =2.573 g cm −3 , λ =0.71073 A, μ =29.0 cm −1 , F (000)=790, T =293 K, R =0.0346, w R =0.0432 for 198 variables and 2278 contributing unique reflections. The structure is characterized by corner- and edge-sharing deformed CoO 5 trigonal bipyramids with PO 4 tetrahedra forming an infinite ribbon along the [010] direction. The ribbons are connected by bridging CoO 6 octahedra resulting in a novel three-cobalt polymeric coordination unit and a polyhedral sheet. The same sheets are packed along the c -axis by sandwiching Na + cations and hydrogen-bonded water molecules to construct the whole structure. The temperature dependence of the magnetic susceptibility of the compound follows the Curie–Weiss law, and the effective magnetic moment of 4.69 μ B corresponds to high-spin Co 2+ ion, confirmed by bond valence sum calculations.