Reference

Study of iron orthophosphate crystal hydrates

Study of iron orthophosphate crystal hydrates. Volkov, A. I.; Yaglov, V. N.; Novikov, G. I. 13824-49-2 and 13463-10-0 are also occured in this study. (Beloruss. Tekhnol. Inst. im. Kirova, Minsk, USSR). Izv. Vyssh. Uchebn. Zaved., Khim. Khim. Tekhnol., 19(8), 1278-9 (Russian) 1976. CODEN: IVUKAR. DOCUMENT TYPE: Journal CA Section: 69 (Thermodynamics, Thermochemistry, and Thermal Properties) By a static tensiometric method, it was detd. that the std. heat of dehydration of synthetic strengite (FePO4.cntdot.2H2O) [13824-49-2] was 16.8 .+-. 0.5 kcal/mole and the corresponding entropy effect was 34.3 .+-. 0.9 entropy units. Absorbed H2O was also present to the extent of 1.4-2.0 moles/mole FePO4.cntdot.2H2O. .

New Iron(III) Phosphate Phases: Crystal Structure and Electrochemical and Magnetic Properties

New Iron(III) Phosphate Phases: Crystal Structure and Electrochemical and Magnetic Properties. Song, Yanning; Zavalij, Peter Y.; Suzuki, Masatsugu; Whittingham, M. Stanley (Departments of Chemistry and Physics and Institute for Materials Research, State University of New York, Binghamton, NY 13902-6016, USA). Inorganic Chemistry, 41(22), 5778-5786 (English) 2002 American Chemical Society. CODEN: INOCAJ. ISSN: 0020-1669. DOCUMENT TYPE: Journal CA Section: 78 (Inorganic Chemicals and Reactions) Section cross-reference(s): 75, 77 Two new Fe(III) phosphates, FePO4, were synthesized from the dehydration of hydrothermally prepd. monoclinic and orthorhombic hydrated phosphates FePO4×2H2O. The structures of both hydrates were redetd. from single crystal data.There are some reagents with their cas registry numbers 13463-10-0 and 7664-38-2 are used in this study. On dehydration, a topotactic reaction takes place with only those bonds assocd. with the H2O mols. being broken, so that both FePO4 phases have essentially the same Fe-P backbone frameworks as the corresponding hydrates. They are, resp., monoclinic FePO4, space group P21/n, a 5.480(1), b 7.480(1), c 8.054(1) ?, b 95.71(1)°, and Z = 4; and orthorhombic FePO4, space group Pbca, a 9.171(1) ?, 9.456(1) ?, c 8.675(1) ?, and Z = 8. Both of these phases are thermally unstable relative to the trigonal quartz-like FePO4. The electrochem. studies find that the orthorhombic Fe phosphate is more active than the monoclinic phase, while both are more active than trigonal FePO4. Both phases approach Curie-Weiss behavior at room temp., with the monoclinic phase exhibiting stronger antiferromagnetic interactions due to Fe-O-Fe interactions. The electrochem. and magnetic data are consistent with the structures of these two compds. The properties of these new Fe phosphate structures are compared with other Fe phosphate phases. .