Crystal structure, magnetic properties and Mössbauer spectroscopy of NaCaFe3(PO4)4

Structural study by X-ray diffraction and Mössbauer spectroscopy of a new synthetic iron phosphate: K4MgFe3(PO4)5

“…During this fit, the linewidth was fixed at 0.30 mm s À1 and the isomer shift was constrained to be identical to the value obtained in the first treatment. The derived isomer shift (d ¼ 0.376(4) mm s À1 ) is close to those (0.35 and 0.38 mm s À1 ) reported for five-coordinated Fe 3+ ions in NaCaFe 3 (PO 4 ) 4 [16]. However, the quadrupole splitting (D m ¼ 0.462 mm s À1 ) is significantly small than those D 1 ¼ 1.15 mm s À1 and D 2 ¼ 1.42 mm s À1 ) reported for NaCaFe 3 (PO 4 ) 4 , indicating a lower deformation of the Fe environment in the title compound.…”

“…Moreover, these materials are of great importance from a fundamental point of view because of their rich structural chemistry owing to the possible (+2/+3) mixed valence of iron and its tendency to adopt 6, 5 and 4 environment polyhedra. Most of the reported structures are built up from isolated FeO 6 , FeO 5 or FeO 4 polyhedra [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18], finite clusters of corner-or edge-sharing Fe polyhedra [19][20][21][22][23][24] or infinite chains of edge-sharing FeO 6 octahedra [25][26][27]. The phosphate groups serve as links for the Fe polyhedral units giving rise to a variety of frameworks which, compared to other mineral phosphates [28,29], can be considered among the most complex ones.…”

Crystal structure, magnetic susceptibility and Mössbauer spectroscopy of the mixed-valence iron phosphate Na1/2Cu4/3Fe2(PO4)3

“…Our recent investigation of iron monophosphates belonging to the A 3 PO 4 -M 3 (PO 4 ) 2 -FePO 4 with A and M are an alkali metal and a divalent cations, respectively, have led to synthesis of several compounds using either a flux method or a solid state reaction techniques [1][2][3][4][5][6][7][8]. The structures of the synthesized compounds consists of bi-or three-dimensional frameworks, in which iron can adopt various environment polyhedra: tetrahedron [2,5], trigonal bipyramid [3,5] or octahedron [1,5,8].…”

“…The structures of the synthesized compounds consists of bi-or three-dimensional frameworks, in which iron can adopt various environment polyhedra: tetrahedron [2,5], trigonal bipyramid [3,5] or octahedron [1,5,8]. These polyhedra are connected together either directly, by corner or edgesharing [3,7] or via the corners or edges of the M polyhedra and the phosphate tetrahedra.…”

Phase relations in the system K2MoO4–KPO3–MoO3–Bi2O3: A new phosphate K3Bi5(PO4)6

“…Using of the selfflux method leads to several difficulties, partially because of high viscosity and the tendency to glass formation in bismuth-containing phosphate systems [16,17]. As it was determined earlier, using the phosphate-molybdate or tungstate fluxes with their rather low viscosity and fine solvent possibilities open an additional opportunity for successful crystal growth [18][19][20][21].…”