Structural investigation of the alluaudite-like mixed-valence iron phosphate: Na1.25Mg1.10Fe1.90(PO4)3
Language
en
Article de revue
This item was published in
Journal of Alloys and Compounds. 2008, vol. 450, n° 1-2, p. 301-305
Elsevier
English Abstract
A new mixed-valence iron phosphate Na1.25Mg1.10Fe1.90(PO4)3 has been synthesized as single crystals by a flux technique and its structure has been refined from X-ray data to a residual R1 = 0.032. The compound crystallizes ...Read more >
A new mixed-valence iron phosphate Na1.25Mg1.10Fe1.90(PO4)3 has been synthesized as single crystals by a flux technique and its structure has been refined from X-ray data to a residual R1 = 0.032. The compound crystallizes in the monoclinic space group C2/c with the parameters: a = 11.7831(3) Å, b = 12.4740(3) Å, c = 6.3761(2) Å, β = 113.643(2)° and Z = 4. The structure belongs to the alluaudite structural type, and thus it obeys to the X(2)X(1)M(1)M(2)2(PO4)3 general formula. The X(2) and X(1) sites are occupied by sodium while the M(1) and M(2) sites feature a statistical distribution of iron and magnesium. Additional information about the cation distribution has been extracted from a Mössbauer spectroscopy study which confirmed the mixed valency of the compound. A magnetic susceptibility study has also been undertaken and has shown the compound to be antiferromagnetic with a Neel temperature of about 35 K.Read less <
Keywords
Alluaudite
Magnetic measurements
Phosphate
X-ray diffraction
Origin
Hal imported