Etude magnétique et par résonance Mössbauer de l'orthophosphate Na 3Fe2(PO4)3α et d'une phase vitreuse dérivée

Abstract

L'étude magnétique et par résonance Mössbauer de Na3Fe2(PO4)303B1 a permis de mettre en évidence un ordre antiferromagnétique à 45,7 K accompagné d'un faible ferromagnétisme. Une trempe après fusion conduit à une phase vitreuse. Son étude indique la présence simultanée de fer divalent et trivalent. Il a été établi que cette réduction du fer était indispensable pour que se produise le processus de vitrification. La structure magnétique du verre est discutée. Abstract. 2014 A study of Na3Fe2(PO4)303B1 by magnetic susceptibility measurements and Môssbauer spectroscopy has shown antiferromagnetic ordering at 45.7 K with some weak ferromagnetism. A vitreous phase has been formed by quenching the molten material. The presence of both divalent and trivalent iron was detected. It has been established that this reduction of iron was necessary to the vitrification process. The magnetic structure of the glass has been discussed.

Magnetic properties of M(PO3)3(M = Fe, Mo). A comparative neutron diffraction study

“…These values are well consistent with the presence of high spin Fe(III) ions in octahedral environment. [30][31][32] The isomer shift value is very close to those observed for other iron containing phosphates. This fact can be attributed to the rather high ionicity of the Fe-O bond giving rise to shorter Fe-O bond distances in good agreement with the structural data.…”

“…This fact can be attributed to the rather high ionicity of the Fe-O bond giving rise to shorter Fe-O bond distances in good agreement with the structural data. 21,31,32 The spectrum recorded at 4 K shows the existence of magnetic order with three types of Fe(III) magnetic cations [see Fig. 5].…”

Structure Refinement and Magnetic Properties of C–Fe(PO3)3 Studied by Neutron Diffraction and Mössbauer Techniques

“…This is in agreement with the previous structural information: the (P}O)}Fe distances are shorter than the (P}O)}P ones ( Table 3). The room temperature values are closed to those observed for another phosphates (e.g., "0.45 for NaFeP O (23) and Na Fe (PO ) (24)). According to Brown and Altermatt (25), the oxidation state of the Fei cation < $ is related to s GH (the valence of the bond between the cation Fei and the anion O H ) by the…”

Synthesis, Crystal Structure, and Magnetic Properties of FeP3SiO11: First Example of Iron(III)Silicophosphate

“…On the whole, it appears that only long-range superexchange occurs in this compound. Actually, the magnitude of the Fe}O}P}O}Fe interaction is an open question, as NeH el temperatures of 29 and 47 K have been reported in NaFeP O (13) and Na Fe (PO ) (14), respectively, and only 4 K in KBaFe (PO ) (15). Moreover, here we have both Fe}O}P}O}Fe and Fe}O}P}O}P}O}Fe interactions and it is clear that we have to consider two types of interactions, intra-and interlayers, from the strongest to the weakest.…”