Electric Field-Induced Unmixing in Mixed Ferrite Spinel (Co,Fe)₃O₄

Abstract:

Unmixing of a semiconducting ferrite spinel, (Co0.203Fe0.797)3O4 in an electric field was examined at 1200oC in its disorder regimes of prevailing (cation) vacancies and interstitials, respectively. It has been found that Co becomes enriched at the cathode in the interstitial-prevailing regime and at the anode in the vacancy-prevailing regime, but to much smaller a degree than expected. This confirms that the direction and degree of unmixing is governed by the difference in electrochemical mobility of the competing cations, and the effective charges of the mobile cations are appreciably reduced from their formal ones by the cross effect between the mobile ions and electrons.

• Periodical: Advances in Science and Technology (Volume 46)
• Pages: 11-20
• DOI: https://doi.org/10.4028/www.scientific.net/AST.46.11
• Online since: October 2006
• Authors: Jeong Oh Hong, H.I. Yoo
• Keywords: (Co,Fe)₃O₄, Cross Effect, Electrotransport, Mixed Ferrite Spinel, Unmixing

References

[1] H. Schmalzried, W. Laqua and P.L. Lin: Z. Naturforsch. Vol. 34a (1979), p.192.

[2] H. Schmalzried and W. Laqua: Oxid. Met. Vol. 15 (1981), p.339.

[3] M. Martin and R. Schmackpfeffer: Solid State Ionics Vol. 72 (1994), p.67.

[4] C.C. Wang, K.S. Goto and S.A. Akbar: J. Electrochem. Soc. Vol. 138 (1996), p.3673.

[5] W.T. Petuskey and H.K. Bowen: J. Am. Ceram. Soc. Vol. 64 (1981), p.611.

[6] D. Dimos, J. Wolfenstine and D.L. Kohlstedt: Acta Metal. Vol. 36 (1988), p.1543.

[7] D. Monceau, M. Filal, M. Tebtoub, C. Petot and G. Petot-Ervas: Solid State Ionics Vol. 73 (1994), p.221.

DOI: 10.1016/0167-2738(94)90037-x

[8] O. Teller and M. Martin: Ber. Bunsenges. Phys. Chem. Vol. 101 (1997), p.1377.

[9] O. Teller and M. Martin: Solid State Ionics Vol. 101-103 (1997), p.475.

[10] P. Franke and R. Dieckmann: Solid State Ionics Vol. 32-33 (1989), p.817.

[11] F.H. Lu and R. Dieckmann: Solid State Ionics Vol. 53-56 (1992), p.290.

[12] J. -O. Hong and H. -I. Yoo: Solid State Ionics Vol. 113-115 (1998), p.265.

[13] H. -I. Yoo and H. L. Tuller: J. Phys. Chem. Solids Vol. 49 (1988), p.761.

[14] R. Dieckmann: J. Phys. Chem. Solids Vol. 59 (1998), p.507.

[15] F. -H. Lu, S. Tinkler and R. Dieckmann: Solid State Ionics Vol. 62 (1993), p.39.

[16] H. -I. Yoo, H. Schmalzried, M. Martin and J. Janek: Z. Phys. Chem. N.F. Vol. 168 (1990), p.129.

[17] E. Aukrust and A. Muan: Trans. TMS-AIME Vol. 230 (1964), p.378.

[18] M. P. Pechini, U. S. Patent, No 3330697, July 11, (1967).

[19] Y. -I. Jang and H. -I. Yoo: Solid State Ionics Vol. 84 (1996), p.77.

[20] H. -I. Yoo and K. -C. Lee: J. Electrochem. Soc. Vol. 145 (1998), p.4243.

[21] K. -C. Lee and H. -I. Yoo: Solid State Ionics Vol. 92 (1996), p.25.

[22] J. -O. Hong and H. -I. Yoo: J. Mater. Res. Vol. 17 (2002), p.1213.

[23] H. -I. Yoo and H. L. Tuller: J. Mater. Res. Vol. 3 (1988), p.552.

[24] J. -H. Kim, H. -I. Yoo and H. L. Tuller: J. Am. Ceram. Soc. Vol. 73 (1990), p.258.

[25] S. -H. Kang, S. -H. Chang and H. -I. Yoo: J. Solid State Chem. Vol. 149 (2000), p.30.

[26] H. Schmalzried, Chemical Kinetics of Solids, VCH, Weinheim, 1995, p.189.

[27] J. -O. Hong, O. Teller, M. Martin and H. -I. Yoo: Solid State Ionics Vol. 123 (1999), p.75.

[28] R. Dieckmann, C. A. Witt and T. O. Mason: Ber. Bunsenges. Phys. Chem. Vol. 90 (1986), p.575.

[29] M. Martin: Ceram. Trans. Vol. 24 (1991), p.91.

[30] H. -I. Yoo and M. Martin: Ceram. Trans. Vol. 24 (1991), p.103.

[31] J. -H. Lee and H. -I. Yoo: J. Electrochem. Soc. Vol. 141 (1994), p.2789.

[32] H. -I. Yoo and J. -H. Lee: Solid State Ionics Vol. 80 (1995), p.5.

[33] H. -I. Yoo and J. -H. Lee: J. Phys. Chem. Solids Vol. 57 (1996), p.65.

[34] H. -I. Yoo and K. -C. Lee: Z. Phys. Chem. N.F. Vol. 207 (1998), p.127.