Influence of hydrothermal powder morphology on the sintered microstructure of MnZn ferrites

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Anderson Dias, Roberto M. Paniago and Vicente T. L. Buono


Abstract

The influence of hydrothermal powder morphology on the sintered microstructure of MnZn ferrites has been analysed. Changes in lattice parameter, particle size, density, size and total volume of pores and in the surface area of the particles were studied as functions of hydrothermal temperature and time. The ferrites were sintered at 1250 °C in a dry nitrogen atmosphere. High density and surface homogeneous ceramic bodies were obtained, without zinc loss by volatilisation. It has been observed that small differences on the properties of the hydrothermal powders gave rise to rather different microstructures after sintering. The effects of the surface chemistry of the nanosized ferrite particles and of the sintering atmosphere employed are discussed, in order to explain this behaviour. Finally, the magnetic character of the ferrite powders as well as of the sintered bodies was analysed at different conditions of temperature and applied magnetic field.


References

  1. H. Toraya, M. Yoshimura and S. Somiya, J. Am. Ceram. Soc., 1982, 65, C72 CAS.
  2. S. Hirano, M. G. M. U. Ismail and S. Somiya, J. Am. Ceram. Soc., 1976, 59, 277 CAS.
  3. S. Hirano, M. Ozawa and S. Naka, J. Mater. Sci., 1981, 16, 1989 CrossRef CAS.
  4. E. D. Kolb, R. L. Barns, R. A. Laudise and J. C. Grenier, J. Cryst. Growth, 1980, 50, 404 CrossRef CAS.
  5. D. Louër, M. T. Mesnier and J. C. Niepce, J. Mater. Sci., 1984, 19, 716 CrossRef CAS.
  6. S. Lowell and J. E. Shields, Powder Surface Area and Porosity, Chapmann & Hall Ltd., New York, NY, 1987 Search PubMed.
  7. A. Dias, V. T. L. Buono, J. M. C. Vilela, M. S. Andrade and T. M. Lima, J. Mater. Sci., 1997, 32, 4715 CrossRef CAS.
  8. S. Komarneni, E. Fregeau, E. Breval and R. Roy, J. Am. Ceram. Soc., 1988, 71, C26 CAS.
  9. A. Dias, R. L. Moreira and N. D. S. Mohallem, J. Phys. Chem. Solids, 1997, 58, 543 CrossRef CAS.
  10. J. Zhao and M. P. Harmer, J. Am. Ceram. Soc., 1988, 71, 113 CAS.
  11. J. Zhao and M. P. Harmer, J. Am. Ceram. Soc., 1992, 75, 830 CAS.
  12. M. J. Readey, R. R. Lee, J. W. Halloran and A. H. Heuer, J. Am. Ceram. Soc., 1990, 73, 1499 CAS.
  13. P. Sainanthip and V. R. W. Amarakoon, J. Am. Ceram. Soc., 1988, 71, 644.
  14. K. Majima, M. Hasegawa, S. Katsuyama, H. Nagai and S. Mishima, J. Mater. Sci. Lett., 1993, 12, 185 CrossRef CAS.
  15. K. Majima, M. Hasegawa, M. Yokota, H. Nagai and S. Mishima, Mater. Trans. JIM, 1993, 34, 556 Search PubMed.
  16. M. Zaharescu, M. Balasoni, M. Crisan, D. Crisan, T. Tavala and V. Moser, Rev. Roum. Chim., 1984, 29, 247 Search PubMed.
  17. O. Kimura and A. Chiba, Adv. Ceram., 1986, 15, 115 Search PubMed.
  18. H. Rikukawa and I. Sasaki, Adv. Ceram., 1986, 15, 215 Search PubMed.
  19. J. Svoboda and H. Riedel, Acta Metall. Mater., 1992, 40, 2829 Search PubMed.
  20. J. Svoboda and H. Riedel, Acta Metall. Mater., 1993, 41, 1929 Search PubMed.
  21. M. Drofenik and S. Besenicar, Am. Ceram. Soc. Bull., 1986, 65, 656 CAS.
  22. T. Pannaparayil, R. Marande and S. Komarneni, J. Appl. Phys., 1991, 69, 5349 CrossRef CAS.
  23. W. Kündig, H. Bömmel, G. Constabaris and H. Lindquist, Phys. Rev, 1966, 142, 327 Search PubMed.
  24. H. H. Joshi, P. B. Pandya and R. G. Kulkarni, Solid State Comm., 1993, 86, 807 CrossRef CAS.
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