Canada - Memorial University of Newfoundland

and reacted with aqueous sodium phosphate (NalP04 - 2.5, [P04] - 1.0 molal) at 250°C
for a period of8 days to produce a red-orange, crystalline solid. The powder XRD
results are listed in Table A.L6 in Appendix L No evidence for unreacled starting
material could be found visually or in the powder XRD spectrum. This synthesis seemed
to produce a solid product with little or no impurities however some extra peaks were
observed that are not present in the SlHP XRD powder pattern from Quinlan (1996). The
presence ofNa)P04 and FC3PO, in the sample accounts for some ofthe peaks, however
the peaks observed at d-spacings 0£7.9707 A and 7.8460 A could not be accounted for.
Figure 3.4 is the SEM image ofthe product. The SEM elemental analysis cantioned the
presence of iron, sodium, and phosphorus. Distinct thin, needle-like crystals can be seen,
much like thc SIHP products obtained from the FelllNTA reactions. While the crystals
were bigger than in previous SIHP syntheses, they were still too small to perfonn single
crystal XRD. The crystals were not unifonn and there appear to be many crystal
[ragments scaltereO throughout the sample. However various areas ofthe SEM image
show that the crystals grew in layers of smaller parallel crystals.
Again this method gave better crystals than in the first approach, described in
Section 3.2.1 but a few impurities were observed. Future work on this reaction could
include trying the synthesis at a higher NalP04 mole ratio.
J.J (NH4)Fc II Fe lll (p04h
The mixed valence compound {NH4)Fe Il Fe Jll (P04h was synthesized by Boudin and
Lii (1998) at 500 °C as a black crystalline product. The objective was to see jfthe mixed
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