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

Structural and Electrical Properties of Novel Cr/Fe Mixed Transition-Metal Phosphates

“…The P–O bond lengths in the P(1)­O 4 tetrahedron range from 1.515 to 1.583 Å and from 1.510 to 1.580 Å for Cr1Fe0 and Cr0.5Fe0.5, respectively, and in the P(2)­O 4 tetrahedron from 1.498 to 1.558 Å for Cr1Fe0 and from 1.451 to 1.576 Å for Cr0.5Fe0.5. The average ⟨P(1)–O⟩ (1.552 and 1.534 Å for Cr1Fe0 and Cr0.5Fe0.5, respectively) and ⟨P(2)–O⟩ (1.522 Å for Cr1Fe0 and 1.529 Å for Cr0.5Fe0.5) distances are close to those reported for some monophosphate compounds. , …”

“…The average ⟨P(1)−O⟩ (1.552 and 1.534 Å for Cr1Fe0 and Cr0.5Fe0.5, respectively) and ⟨P(2)−O⟩ (1.522 Å for Cr1Fe0 and 1.529 Å for Cr0.5Fe0.5) distances are close to those reported for some monophosphate compounds. 62,63 All of the P−O distances have an overall value of less than 1.557 Å (Table T3) and P−O 4 DIs lower than 5.4% (Table T3). However, all coordination polyhedra P(i)O 4 are slightly distorted in the case of Cr1Fe0 with DI4 = 0.0164 for P(1)O 4 compared to DI4 = 0.0163 for P(2)O 4 and with DI4 = 0.0256 for P(1)O 4 , which is very high compared to DI4 = 0.0152 for P(2)O 4 in the case of Cr0.5Fe0.5.…”

The solid solution K3.84Ni0.78Fe3.19(PO4)5

“…The main difference between the obtained solid solution and the phosphate K 4 MgFe 3 (PO 4 ) 5 (Hidouri et al, 2008) is the splitting of the K + site in two positions. The occupation of the K1B site (0.23 (3)) correlates with the increase of the iron content (from 3 to 3.…”

“…The distances (Ni/Fe)-O vary between 1.908 (3) and 1.979 (3) Å. The average distance ((Ni/Fe)-O) = 1.937 Å is slightly less than that in K 4 MgFe 3 (PO 4 ) 5 (d((Mg/Fe)-O) = 1.952 Å) (Hidouri et al, 2008). The tetrahedral orthophosphate anions deviate only slightly from ideal values with P-O bond lengths ranging from 1.510 3to 1.542 (3) Å.…”

“…Herein, the structure of the solid solution K 3.84 Ni 0.78 Fe 3.19 (PO 4 ) 5 , tetrapotassium tetra(nickel(II)/iron(III)) pentakis-(orthophosphate), (I), is reported. The crystal structure of (I) is isotypic with K 4 MgFe 3 (PO 4 ) 5 (Hidouri et al, 2008).…”