K1+2 Ni1- Fe2(AsO4)3 (x = 0,125): un nouvel arséniate à structure de type α-CrPO4
Ridha Ben Smail1, Mohamed Faouzi Zid2
1Université de Tunis El Manar, Faculté des Sciences de Tunis, Laboratoire de Matériaux, Cristallochimie et Thermodynamique Appliquée, 2092 El Manar II, Tunis, Tunisia; Université de Carthage, Institut Préparatoire aux Etudes d'Ingénieurs de Nabeul, Campus Universitaire, 8000 Mrazka, Nabeul, Tunisia.
Abstract:
A new arsenate K1+2 Ni1- Fe2(AsO4)3 (x = 1/8) {potassium nickel diiron(III) tris-[arsenate(V)]} was synthesized using a flux method and its crystal structure was determined from single-crystal X-ray diffraction data. This material was also characterized by qualitative energy dispersive X-ray spectroscopy (EDS) analysis. The crystal structure belongs to the α-CrPO4-structure type, space group Imma. It consists of a three-dimensional-framework built up from FeO6 and Ni0.875□1.25O6-octa-hedra and AsO4-tetra-hedra that are sharing corners and/or edges, generating tunnels running along the [010] and [001] directions in which the potassium cations are located. The proposed structural model was validated by bond-valence-sum calculations, charge-distribution (CHARDI) and Madelung energy analyses.
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