Showing papers by "J. Paul Attfield published in 1993"
TL;DR: In this paper, the crystal structures of the cobalt and nickel derivatives have been determined by refinement of X-ray powder diffraction data, and they have been synthesized through soft hydrothermal treatments.
Abstract: Crystalline microporous phosphites of transition metal ions, have been synthesized through soft hydrothermal treatments. The crystal structures of the cobalt and nickel derivatives have been determined by refinement of X-ray powder diffraction data.
78 citations
40 citations
TL;DR: The structures of the two new lamellar oxophosphorus compounds of nickel(II), Ni(HPO 3 )-H 2 O (1) and NiCl(H 2 PO 2 ).H 2O (2) have been determined by X-ray methods.
Abstract: The structures of the two new lamellar oxophosphorus compounds of nickel(II), Ni(HPO 3 )-H 2 O (1) and NiCl(H 2 PO 2 ).H 2 O (2), have been determined by X-ray methods. The simple phosphite (I) crystallizcs in an orthorhombic system, space group Pca2 1 (a=8.8982(2) A, b=7.8628(2) A, c=10.0333(3) A, V=701.98(5) A 3 , Z=4), and is isostructural with Co(HPO 3 ).H 2 O. The chlorohypophosphite (2) also crystallizes in an orthorhombic system, space group Pbca
21 citations
TL;DR: In this paper, the structure of a monoclinically-distorted CuSO4 type structure was determined from laboratory X-ray powder diffraction data using the Rietveld method (RwP = 7.4%, Rp = 5.5%, and RF = 2.7%).
Abstract: Mn111XOcnH20 (X = P, As; n = 1.0-1.5) phases have been characterized through electron microscopy, density measurements, thermal analysis, and X-ray powder diffraction. Samples with n > 1 behave as intergrowths of stoichiometric, crystalline MnXOcH20 and amorphous MnX04.mH20 with m - 4. A detailed study of the thermal behavior of these systems has revealed that the presence of the amorphous phase strongly affects the dehydration and reduction temperatures. The phosphate and arsenate always decompose through different pathways, as the phosphate undergoes reduction of Mn3+ to Mn2+ before water loss commences, whereas the arsenate shows a reversible dehydration before being irreversibly reduced. This has enabled the simple new salt MnAs04 to be prepared by careful decomposition of MnAsOcnH20, and the crystal structure (monoclinic, space group P2'/n, a = 6.679(3) A, b = 8.940(3) A, c = 4.791(2) A, j3 = 93.76(4)O) has been determined from laboratory X-ray powder diffraction data using the Rietveld method (RwP = 7.4%, Rp = 5.5%, and RF = 2.7%). This arrangement is a unique example of a monoclinically-distorted CuSO4 type structure. Chains of edge-sharing MnO6 octahedra containing two different Mn3+ sites that display cooperative [4 + 21 and [2 + 2 + 21 Jahn-Teller distortions are linked through distorted AS04 groups.
15 citations