A Mössbauer effect study of the electronic and structural properties of Fe9(PO4)O8

Spectroscopic and Magnetic Properties of α-Li3Fe2(PO4)3: A Two-Sublattice Ferrimagnet

“…The Mössbauer data at 4.2 K can be attributed to a single magnetic spectrum of δ = 0.546(6) mm s -1 and B = 54.9(4) T. These parameters are consistent with those obtained for other iron(III) phosphate compounds. − At lowest temperatures, the hyperfine field is close to saturation at a value very near to the expected one of 55.0 T…”

Hydrothermal Synthesis, Structural Characterization, and Physical Properties of a New Mixed Valence Iron Phosphate, SrFe3(PO4)3

“…Indeed, very similar spectra to those shown in Fig. 4 have been observed (32) between 295 and 220 K for -Fe (PO )O, and the 295 K iron(III) isomer shift reported in Table 5 is only slightly smaller than that of the iron(III) site in -Fe (PO )O and to the values found in a series of structurally related iron(III) phosphates (31). In contrast, the 295 K iron(II) isomer shift of 1. value observed in -Fe (PO )O, presumably because the former compound has a substantially shorter 2.119 A s average iron(II) to oxygen bond distance than the 2.141 A s average distance found (34) for Fe> and Fe>, respectively.…”

Hydrothermal Synthesis, Structure, and Characterization of a Mixed-Valent Iron(II/III) Phosphate, NaFe3.67(PO4)3: A New Variation of the Alluaudite Structure Type

“…Indeed, in view of the nonstoichiometric nature of NaFe (PO ) , it is surprising how well resolved are the observed spectra and how small are the observed doublet linewidths (Table 6). The hyperfine parameters given in Table 6 are completely consistent with the electronic properties of NaFe (PO ) and with those obtained from related compounds (28)(29)(30)(31)(32). The isomer shifts, , and the quadrupole splittings, E / , for the Fe(1) and Fe(2) sites are clearly indicative of iron (II) in highly distorted octahedral coordination environments (30,31).…”

“…The isomer shift for this site is completely consistent with the iron(III) oxidation state assigned to this iron and is very typical of iron(III) in related mixed-valent (28,29) and non-mixed-valent compounds. More unusual is the rather small quadrupole splitting observed for Fe(3), the site which has a square-planar coordination environment.…”