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KNi 0.93 Fe II 0.07 Fe III (PO 4 ) 2 : a new type of structure for a compound of composition M I M II M III (PO 4 ) 2
Author(s) -
Strutynska Nataliya Yu.,
Zatovsky Igor V.,
Baumer Vyacheslav N.,
Ogorodnyk Ivan V.,
Slobodyanik Nikolay S.
Publication year - 2014
Publication title -
acta crystallographica section c
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.304
H-Index - 17
ISSN - 2053-2296
DOI - 10.1107/s2053229614000679
Subject(s) - crystallography , chemistry , nickel , atom (system on chip) , type (biology) , population , polyhedron , crystal structure , materials science , combinatorics , mathematics , ecology , demography , organic chemistry , sociology , computer science , biology , embedded system
The solid solution KNi 0.93 Fe II 0.07 Fe III (PO 4 ) 2 {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 M I M II M III (PO 4 ) 2 . The framework is formed by [(Ni/Fe)O 6 ] polyhedra [Fe site occupancy = 0.069 (14)] linked via shared oxygen vertices forming a cis ‐like parallel chain stretching along a and [FeO 5 ] polyhedra (located on alternate sides of the chains) connected via two types of PO 4 groups into a three‐dimensional structure. The K atoms are disordered between two sites, denoted K1 A and K1 B , with occupancies of 0.930 (9) and 0.070 (9), respectively, and reside inside channels along the a axis. Calculations of the Voronoi–Dirichlet polyhedra of the K atoms give a coordination scheme for K1 A of [9 + 3] and for K1 B of [10 + 2]. The most remarkable feature of the structure is the splitting of the K‐atom site and the population of the K1 A and K1 B positions due to substitution of Ni by Fe in the (Ni/Fe) position.