Abstract
Two different polymorphs of ferrous oxalate dihydrate were synthesized by precipitation of ferrous ions with oxalic acid: α-Fe(C2O4) · 2H2O with a monoclinic unit cell is obtained after precipitation and ageing at 90 °C, whereas the orthorhombic β-type is formed after precipitation at room temperature. The morphology of the oxalate crystals can be tailored from prismatic crystals of the α-polymorph over star-like aggregates of α/β-mixtures to non-agglomerated crystallites of β-oxalate. Thermal decomposition in air gives hematite at T ≥ 250 °C; if the thermolysis reaction is performed at low oxygen partial pressures (e.g., T = 500 °C and p O2 = 10−25 atm) magnetite is obtained. The synthesized magnetite is stoichiometric as signaled by lattice parameters of a 0 = 8.39 Å. The thermal decomposition of ferrous oxalate is monitored by thermal analysis, XRD, and IR-spectroscopy. The morphology of the oxalate crystals is preserved during thermal decomposition; the oxalates are transformed into spinel particle aggregates of similar size and shape. The crystallite size of the magnetite particles increases with temperature and is 40 or 55 nm, if synthesized from β-oxalate at 500 °C or 700 °C, respectively. The saturation magnetization of the magnetite particles decreases with decreasing particle size. Since the particles are larger than the critical diameter for superparamagnetic behavior they display hysteresis behavior at room temperature.
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Manasse E (1910) Rend Acc Naz Lincei 19:138
Mazzi F, Garavelli C (1957) Period Mineral 26:269
Carić S (1959) Bull Soc franc Min Crist 82:50
Deyrieux R, Peneloux A (1969) Bull Soc Chim Fr 8:2675
Rao V, Shashimohan AL, Biswas AB (1974) J Mater Sci 9:430–433. doi:https://doi.org/10.1007/BF00737843
Glenn Rupard R, Gallagher PK (1996) Thermochim Acta 272:11. doi:https://doi.org/10.1016/0040-6031(95)02626-6
Frost RL, Weier ML (2004) J Therm Anal Calorim 75:277. doi:https://doi.org/10.1023/B:JTAN.0000017349.31035.dd
Mohamed MA, Galwey AK, Halawy SA (2005) Thermochim Acta 429:57. doi:https://doi.org/10.1016/j.tca.2004.08.021
Hermanek M, Zboril R, Mashlan M, Machala L, Schneeweiss O (2006) J Mater Chem 16:1273. doi:https://doi.org/10.1039/b514565a
Hermanek M, Zboril R, Medrik I, Pechousek J, Gregor C (2007) J Am Chem Soc 129:10929. doi:https://doi.org/10.1021/ja072918x
Zhou W, Tang K, Zeng S, Qi Y (2008) Nanotechnology 19:065602. doi:https://doi.org/10.1088/0957-4484/19/6/065602
Cornell RM, Schwertfeger U (2003) The Iron Oxides, Viley VCH
Hergt R, Hiergeist R, Zeissberger M, Schüler D, Heyen U, Hilger I et al (2005) J Magn Magn Mater 293(205):80–86
Welo LA, Baudisch O (1925) Phil Mag 50(IV):399
David I, Welch AJE (1956) Trans Faraday Soc 52:1642. doi:https://doi.org/10.1039/tf9565201642
Massart R (1981) IEEE Trans Magn 17:1247. doi:https://doi.org/10.1109/TMAG.1981.1061188
Faivre D, Agrinier P, Menguy N, Zuddas P, Pachana K, Gloter A et al (2004) Geochim Cosmochim Acta 68(21):4395. doi:https://doi.org/10.1016/j.gca.2004.03.016
Vassierres L, Chaneac C, Tronc E, Jolivet JP (1998) J Colloid Interface Sci 205:205. doi:https://doi.org/10.1006/jcis.1998.5614
Mürbe J, Rechtenbach A, Töpfer J (2008) Mater Chem Phys 110:426. doi:https://doi.org/10.1016/j.matchemphys.2008.02.037
Dutz S, Hergt R, Mürbe J, Müller R, Zeisberger M, Andrä W et al (2007) J Magn Magn Mater 308:305. doi:https://doi.org/10.1016/j.jmmm.2006.06.005
Xuan S, Chen M, Hao L, Jiang W, Gong X, Hu Y et al (2008) J Magn Magn Mater 320:164. doi:https://doi.org/10.1016/j.jmmm.2007.05.019
Gabal MA, Ata-Allah SS (2004) J Phys Chem Solids 65:995. doi:https://doi.org/10.1016/j.jpcs.2003.10.059
Muan A, Osborn EF (1965) Phase equilibria among oxides in steelmaking. Addison-Wesley Publ. Company, Redding, USA
Jørgensen JE, Mosegaard L, Thomsen LE, Jensen TR, Hanson JC (2007) J Solid State Chem 180:180. doi:https://doi.org/10.1016/j.jssc.2006.09.033
Gillot B (1994) Vibrat Spectr 6:127. doi:https://doi.org/10.1016/0924-2031(94)85001-1
Kustova GN, Burgina EB, Sadykov VA, Poryvaev SG (1992) Phys Chem Miner 18:379. doi:https://doi.org/10.1007/BF00199419
Musić S, Popović S, Ristić M (1993) J Mater Sci 28:632. doi:https://doi.org/10.1007/BF01151237
White WB, DeAngelis BA (1967) Spectrochimica Acta 23A:985
Ishii M, Nakahira M, Yamanaka T (1972) Solid State Commun 11:209. doi:https://doi.org/10.1016/0038-1098(72)91162-3
Coey JMD, Khalafalla D (1972) Phys Status Solidi 11:229. a. doi:https://doi.org/10.1002/pssa.2210110125
Dunlop DJ (1973). Geophys Res 78(11):1780. doi:https://doi.org/10.1029/JB078i011p01780
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The authors thank Mrs. S. Müller and M. Friedrich (FH Jena) for oxalate preparations and SEM investigations, respectively.
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Angermann, A., Töpfer, J. Synthesis of magnetite nanoparticles by thermal decomposition of ferrous oxalate dihydrate. J Mater Sci 43, 5123–5130 (2008). https://doi.org/10.1007/s10853-008-2738-3
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DOI: https://doi.org/10.1007/s10853-008-2738-3