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Ben Salah M Vilminot S André G Richard-Plouet M Bourée-Vigneron F Mhiri T Kurmoo M 《Chemistry (Weinheim an der Bergstrasse, Germany)》2004,10(8):2048-2057
[Mn(3)(OH)(2)(SO(4))(2)(H(2)O)(2)] and its deuterated analogue were synthesized by a hydrothermal technique and characterized by differential thermal analysis, thermogravimetric analysis, and IR spectroscopy. Its nuclear structure, determined by single-crystal X-ray analysis and Rietveld analysis of neutron powder-diffraction data, consists of a 3D network of chains of edge-sharing Mn(1)O(6), running along the c axis, connected by the apices of Mn(2)O(6) and SO(4) units. It is isostructural to the nickel analogue. Determination of the magnetic structure and measurements of magnetization and heat capacity indicate the coexistence of both magnetic long-range ordering (LRO) and short-range ordering (SRO) below a Néel temperature of 26 K, while the SRO is retained at higher temperatures. The moments of the two independent Mn atoms lie in the bc plane, and that of Mn(1) rotates continuously by 54 degrees towards the c axis on decreasing the temperature from 25 to 1.4 K. While the SRO may be associated with frustration of the moments within a Mn(3) trimer, the LRO is achieved by antiparallel alignment of the four symmetry-related trimers within the magnetic unit cell. A spin-flop field, measured by dc and ac magnetization on a SQUID, is observed at 15 kOe. 相似文献
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Walid Rekik Houcine Naïli Tahar Mhiri 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(4):i50-i52
Potassium gadolinium polyphosphate, KGd(PO3)4, was synthesized using the flux method. The atomic arrangement consists of an infinite long‐chain polyphosphate organization. Two types of chains, with a period of eight PO4 tetrahedra, run along the [101] direction. The Gd atoms have an eightfold coordination, while the K atoms have nine O‐atom neighbours. 相似文献
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Adel Mahroug Mohamed Belhouchet Annie Hémon-Ribaud Tahar Mhiri 《Phosphorus, sulfur, and silicon and the related elements》2013,188(12):2332-2340
Abstract A new adduct 3-ammoniumphenyl sulfone dihydrogenphosphate phosphoric acid, [C12H14N2O2S](H2PO4)2H3PO4, has been synthesized by slow evaporation at room temperature using 3-aminophenyl sulfone as the structure-directing agent. The structure, determined by single-crystal X-ray diffraction at 293 K, can be described as inorganic layers built by H2PO4 ? groups and H3PO4 molecules, parallel to the (a, c) planes at y = 0.5, between which molecules of the organic group [C12H14N2O2S]2+ are inserted. In this atomic arrangement, hydrogen bonds and van der Waals interactions between the different species play an important role in the tri-dimensional network cohesion. Solid-state 13C and 31P MAS NMR spectroscopies are in agreement with the X-ray structure. [Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements for the following free supplemental resource: Tables S1 and S2. Figures S1 and S2.] GRAPHICAL ABSTRACT 相似文献
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Fathia Rajah Mohsen Graia Tahar Mhiri 《Phosphorus, sulfur, and silicon and the related elements》2013,188(9):1244-1253
Abstract Sodium copper (II) arsenate Na7Cu4(AsO4)5 has been grown by conventional high-temperature, solid-state methods in molten-salt media. It was characterized by single crystal X-ray diffraction (XRD), thermal analysis (DTA–TGA), scanning electron microscopy (SEM), semiquantitative energy dispersive spectroscopy analysis (EDS), and vibrational spectroscopy. Na7Cu4(AsO4)5 exhibits a three-dimensional framework built up of CuO5, CuO4, and AsO4 polyhedra, with intersecting channels in which the Na+ cations are located. The three-dimensional cohesion of the framework results from Cu–O–As bridges. CuO5 and CuO4 polyhedra are elongated due to the Jahn–Teller effect, whereas AsO4 tetrahedra are almost regular. This new structural model is validated by the charge distribution (CD) analysis. The infrared and Raman spectra confirmed the presence of AsO4 tetrahedra. [Supplementary materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfer, and Silicon and the Related Elements for the following free supplemental files: Additional tables and figures.] 相似文献
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Ben Salah M Vilminot S Richard-Plouet M André G Mhiri T Kurmoo M 《Chemical communications (Cambridge, England)》2004,(22):2548-2549
The synthetic mineral Co(II)5(OH)6(SO4)2(H2O)4 (1), obtained by hydrothermal reaction of CoSO4.7H2O and NaOH at 165 degrees C and consisting of brucite-like Co4(OH)6O2 layers pillared by OSO3-Co(H2O)4-O3SO, is a ferromagnet (T(Curie)= 12 K, Hc= 580 Oe). 相似文献
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The X-ray diffraction, vibrational and impedance spectroscopy studies of (Cs)0.26(Rb)0.74H(SO4)0.89(SeO4)0.11 (CsRbHSSe) new solid solution are presented. The title compound undergo a superionic phase transition (SPT) at This transition was confirmed by an abrupt increase of conductivity. The bulk impedance parameters of CsRbHSSe, RbH(SO4)0.81(SeO4)0.19 (RbHSSe) and CsH(SO4)0.76(SeO4)0.24 (CsHSSe) were determined from an analysis of AC conductivity data measured in a wide temperature range. The charge carriers concentration in the samples investigated has been evaluated using the Almond-West formalism and shown to be independent of temperature. 相似文献
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Maalej W Vilminot S André G Damay F Elaoud Z Mhiri T Kurmoo M 《Inorganic chemistry》2011,50(8):3286-3294
We report the syntheses, crystal structures, and magnetic properties of KMn(2)(H(3)O(2))(MoO(4))(2) (MnH), KMn(2)(D(3)O(2))(MoO(4))(2) (MnD), KFe(2)(H(3)O(2))(MoO(4))(2) (FeH), KFe(2)(D(3)O(2))(MoO(4))(2) (FeD), KCo(2)(H(3)O(2))(MoO(4))(2) (CoH), and KCo(2)(D(3)O(2))(MoO(4))(2) (CoD), and the magnetic structures of MnD and FeD. They belong to the structural variant (space group I2/m) of the mineral natrochalcite NaCu(2)(H(3)O(2))(SO(4))(2) (space group C2/m) where the diagonal within the ac-plane of the latter become one axis of the former. The structure of MnD, obtained from Rietveld refinement of a high-resolution neutron pattern taken at 300 K, consists of chains of edge-sharing octahedra bridged by MoO(4) and D(3)O(2) to form layers, which are connected to K through the oxygen atoms to form the three-dimensional (3D)-network. The X-ray powder diffraction patterns of the other two compounds were found to belong to the same space group with similar parameters. The magnetic susceptibilities of MnH and FeH exhibit long-range ordering of the moments at a Ne?el temperature of 8 and 11 K, respectively, which are accompanied by additional strong Bragg reflections in the neutron diffraction in the ordered state, consistent with antiferromagnetism. Analyses of the neutron data for MnD and FeD reveal the presence of both long- and short-range orderings and commensurate magnetic structures with a propagation vector of (?, 0, ?). The moments are antiferromagnetically ordered within the chains with alternation between chains to generate four nonequivalent nuclear unit cells. For MnD the moments are perpendicular to the chain axis (b-axis) while for FeD they are parallel to the b-axis. The overall total is a fully compensated magnetic structure with zero moment in each case. Surprisingly, for KCo(2)(D(3)O(2))(MoO(4))(2) neither additional peaks nor increase of the nuclear peaks' intensities were observed in the neutron diffraction patterns below the magnetic anomaly at 12 K which was identified to originate from a small quantity of a ferromagnetic compound, Co(2)(OH)(2)MoO(4). 相似文献
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