KNi0.93FeII0.07FeIII(PO4)2: a new type of structure for a compound of composition MIMIIMIII(PO4)2. Issue 2 (15th February 2014)

• Record Type: Journal Article
• Authors: Strutynska, Nataliya Yu.; Zatovsky, Igor V.; Baumer, Vyacheslav N.; Ogorodnyk, Ivan V.; Slobodyanik, Nikolay S.
• Is Part Of: Acta crystallographica. Volume 70:Issue 2(2014:Feb.)
• Page Start: 160
• Page End: 164
• Publication Date: 2014-02-15
• Subjects: Crystallography -- Periodicals; Crystals -- Periodicals; 548.3
• DOI: 10.1107/S2053229614000679
• Languages: English
• ISSNs: 2053-2296

Abstract

<abstract abstract-type="main" xml:lang="en"> <title> <x xml:space="preserve">Abstract</x> </title> <p>The solid solution KNi<sub>0.93</sub>Fe<sup>II</sup><sub>0.07</sub>Fe<sup>III</sup>(PO<sub>4</sub>)<sub>2</sub> {potassium [nickel(II)/iron(II)] iron(III) bis(orthophosphate)} has been prepared by the flux method. The compound shows a new type of structure for a phosphate with the general composition <italic>M</italic><sup>I</sup><italic>M</italic><sup>II</sup><italic>M</italic><sup>III</sup>(PO<sub>4</sub>)<sub>2</sub>. The framework is formed by [(Ni/Fe)O<sub>6</sub>] polyhedra [Fe site occupancy = 0.069 (14)] linked <italic>via</italic> shared oxygen vertices forming a <italic>cis</italic>‐like parallel chain stretching along <italic>a</italic> and [FeO<sub>5</sub>] polyhedra (located on alternate sides of the chains) connected <italic>via</italic> two types of PO<sub>4</sub> groups into a three‐dimensional structure. The K atoms are disordered between two sites, denoted K1<italic>A</italic> and K1<italic>B</italic>, with occupancies of 0.930 (9) and 0.070 (9), respectively, and reside inside channels along the <italic>a</italic> axis. Calculations of the Voronoi–Dirichlet polyhedra of the K atoms give a coordination scheme for K1<italic>A</italic> of [9 + 3] and for K1<italic>B</italic> of [10 + 2]. The most remarkable feature of the structure is the splitting of the K‐atom site and the population of the K1<italic>A</italic> and K1<italic>B</italic> positions due to substitution of Ni by Fe in the (Ni/Fe) position.</p> </abstract>