Hostname: page-component-8448b6f56d-mp689 Total loading time: 0 Render date: 2024-04-24T02:08:15.592Z Has data issue: false hasContentIssue false
  • English
  • Français

Microstructural Evolution of Nanocrystalline Magnetite Synthesized by Electrocoagulation

Published online by Cambridge University Press:  03 March 2011

Ying-Chieh Weng ,
I.A. Rusakova ,
Andrei Baikalov ,
J.W. Chen  and
Nae-Lih Wu
Ying-Chieh Weng
Affiliation:
Department of Chemical Engineering, National Taiwan University, Taipei 106, Taiwan, Republic of China
I.A. Rusakova
Affiliation:
Texas Center for Superconductivity and Advanced Materials, University of Houston, Houston, Texas 77204-5932
Andrei Baikalov
Affiliation:
Texas Center for Superconductivity and Advanced Materials, University of Houston, Houston, Texas 77204-5932
J.W. Chen
Affiliation:
Department of Physics, National Taiwan University, Taipei 106, Taiwan, Republic of China
Nae-Lih Wu*
Affiliation:
Department of Chemical Engineering, National Taiwan University, Taipei 106, Taiwan, Republic of China
*
a)Address all correspondence to this author. e-mail: nlw001@ntu.edu.tw
Get access

Abstract

Nanocrystalline magnetite powders were synthesized by an electrocoagulation technique, in which an electric current was passed across two plate electrodes of carbon steel immersed in NaCl(aq) electrolyte, and the microstructure of the oxide powder was found to evolve in roughly three stages. The first stage involves formation and growth of severely defective colloidal crystallites. This is followed by agglomeration among the oxide crystallites to form mesoporous agglomerates containing predominantly inter-crystallite pores, and the average crystallite size was found to reach a plateau. Finally, coarsening of the crystallites within the agglomerates leads to another rapid increase in crystallite size and reduction in pore opening. The synthesized powders typically showed a saturation magnetization of ∼75 emu/g and a coercivity Hc of ∼118 Oe. A mechanism involving competition between nucleation and growth of free colloids and coarsening of the skeletal framework was proposed to explain the temporary level-off in crystallite size during the synthesis.

Keywords

ColloidalElectrochemical synthesisMagnetic
Type
Articles
Information
Journal of Materials Research , Volume 20 , Issue 1 , January 2005 , pp. 75 - 80
Copyright
Copyright © Materials Research Society 2004

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1Bohacek, J., Subrt, J., Hanslik, T. and Tlaskal, J.: Preparing particulate magnetites with pigment properties from suspensions of basic iron(III) sulfates with the structure of Jarosite. J. Mater. Sci. 28, 2827 (1993).CrossRefGoogle Scholar
2Comstock, R.L.: Modern magnetic materials in data storage. J. Mater. Sci. Mater. Electron. 13, 509 (2002).CrossRefGoogle Scholar
3Wu, K.T., Kuo, P.C., Yao, Y.D. and Tsai, E.H.: Magnetic and optical properties of Fe3O4 nanoparticles ferrofluids prepared by coprecipitation technique. IEEE Trans. Magn. 37(4), 2651–2653 (2001).CrossRefGoogle Scholar
4Shinkai, M.: Functional magnetic particles for medical application. J. Biosci. Bioeng. 94, 606 (2002).CrossRefGoogle ScholarPubMed
5Perez, J.M., Simeone, F.J., Saeki, Y., Josephson, L. and Weissleder, R.: Viral-induced self-assembly of magnetic nanoparticles allows the detection of viral particles in biological media. J. Am. Chem. Soc. 125, 10192 (2003).CrossRefGoogle ScholarPubMed
6Beydoun, D., Amal, R., Low, G.K.C., McEvoy, S.: Novel photocatalyst: Titania-coated magnetite. Activity and photodissolution. J. Phys. Chem. B 104, 4387 (2000).CrossRefGoogle Scholar
7Kang, Y.S., Risbud, S., Rabolt, J.F. and Stroeve, P.: Synthesis and characterization of nanometer-size Fe3O4 and γ–Fe2O3 particles. Chem. Mater. 8, 2209 (1996).CrossRefGoogle Scholar
8Lee, H.S., Lee, W.C. and Furubayashi, T.: A comparison of coprecipitation with microemulsion methods in the preparation of magnetite. J. Appl. Phys. 85, 5231 (1999).CrossRefGoogle Scholar
9Diamandescu, L., Mihaila-Tarabasanu, D., Teodorescu, V. and Popescu-Pogrion, N.: Hydrothermal synthesis and structural characterization of some substituted magnetites. Mater. Lett. 37, 340 (1998).CrossRefGoogle Scholar
10Li, Y., Liao, H., Qian, Y.: Hydrothermal synthesis of ultrafine α–Fe2O3 and Fe3O4 powders. Mater. Res. Bull. 33, 841 (1998).CrossRefGoogle Scholar
11Bae, D.S., Han, K.S., Cho, S.B. and Choi, S.H.: Synthesis of ultrafine Fe3O4 powder by glycothermal process. Mater. Lett. 37, 255 (1998).CrossRefGoogle Scholar
12Sun, S. and Zeng, H.: Size-controlled synthesis of magnetite nanoparticles. J. Am. Chem. Soc. 124, 8204 (2002).CrossRefGoogle ScholarPubMed
13Khollam, Y.B., Dhage, S.R., Potdar, H.S., Deshpande, S.B., Bakare, P.P., Kulkarni, S.D. and Date, S.K.: Microwave hydrothermal preparation of submicron-sized spherical magnetite (Fe3O4) powders. Mater. Lett. 56, 571 (2002).CrossRefGoogle Scholar
14Dhage, S.R., Khollam, Y.B., Potdar, H.S., Deshpande, S.B., Bakare, P.P., Sainkar, S.R. and Date, S.K.: Effect of variation of molar ratio (pH) on the crystallization of iron oxide phases in microwave hydrothermal synthesis. Mater. Lett. 57, 457 (2002).CrossRefGoogle Scholar
15Tsouris, C., Depaoli, D.W. and Shor, J.T. Method and apparatus to electrolytically produce high-purity magnetite particles, U.S. Patent No. 6 179 987(2001).Google Scholar
16Tsouris, C., DePaoli, D.W., Shor, J.T., Hu, M.Z.C. and Ying, T.Y.: Electrocoagulation for magnetic seeding of colloidal particles. Colloids Surf. A 177, 223 (2001).CrossRefGoogle Scholar
17Ying, T.Y., Yiacoumi, S. and C., Tsouris: An electrocoagulation method for the formation of magnetite particles. J. Disp. Sci. Technol. 23, 569 (2002).CrossRefGoogle Scholar
18Wu, N.L., Wang, S.Y., Han, C.Y., Wu, D.S. and Shiue, L.R.: Electrochemical capacitor of magnetite in aqueous electrolytes. J. Power Sources 113, 173 (2003).CrossRefGoogle Scholar
19Jones, F.W.: The measurement of particle size by the x-ray method. Proc. Roy. Soc. (London) 166A, 16 (1938).Google Scholar
20Lee Pan, R. and Banfield, J.F.: Morphology development and crystal growth in nanocrystalline aggregates under hydrothermal conditions: Insight from titania. Geochimi. Cosmochimi. Acta 63, 1549 (1999).Google Scholar
21Yeadon, Y., Ghaly, M., Yang, J.C., Averback, R.S. and Gibson, J.M.: Contact epitaxy observed in supported nanoparticles. Appl. Phys. Lett. 73, 3208 (1998).CrossRefGoogle Scholar
22Banfield, J.F., Welch, S.A., Zhang, H., Ebert, T.T. and Penn, R.L.: Aggregation-based crystal growth and microstructure development in natural iron oxyhydroxide biomineralization products. Science 289, 751 (2000).CrossRefGoogle ScholarPubMed