Hostname: page-component-8448b6f56d-xtgtn Total loading time: 0 Render date: 2024-04-24T06:32:58.758Z Has data issue: false hasContentIssue false
  • English
  • Français

Structure and Magnetic Properties of Co, Ni, Mn, Cr and Cu Substituted Magnetites

Published online by Cambridge University Press:  10 February 2011

M. Sorescu ,
D. Mihaila-Tarabasanu  and
L. Diamandescu
M. Sorescu
Affiliation:
Duquesne University, Bayer School of Natural and Environmental Sciences, Physics Department, Pittsburgh, Pennsylvania 15282, U.S.A.
D. Mihaila-Tarabasanu
Affiliation:
Institute of Atomic Physics, National Institute of Materials Physics, R-76900 Bucharest-Magurele, Romania
L. Diamandescu
Affiliation:
Institute of Atomic Physics, National Institute of Materials Physics, R-76900 Bucharest-Magurele, Romania
Get access

Abstract

Co, Ni, Mn, Cr and Cu substituted magnetites were prepared by the hydrothermal method at 300°C, with concentrations x ranging from 8.2 to 12.5%. Transmission electron microscopy determined the average particle diameter <Φ> to be in the hundred of nm range and the morphological modifications induced by the various substitutions employed. Hysteresis loop measurements were performed to determine the coercive field Hc and saturation magnetic moment ms. While Hc decreased with increasing <Φ>, the particle shape was found to play an important role in explaining the dependence of ms on <Φ>. Transmission Mössbauer spectroscopy was used to determine the site preference of the substitutions and their effect on the hyperfine magnetic fields. The room temperature Mossbauer spectra were analyzed assuming a random distribution of substitutents using the binomial distribution from the ionic crystal point of view. Superparamagnetic particles were observed at room temperature in the case of Cu and Cr substituted magnetites.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 517: Symposium F – Wide Bandgap Semiconductors for High Power, High Frequency , January 1998 , 337
Copyright
Copyright © Materials Research Society 1998

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

1. Sorescu, M., J. Mat. Sci. Lett., in print.Google Scholar
2. Okamura, A., Nakamura, S., Tanaka, M. and Siratori, K., J. Phys. Soc. Jpn. 64, 3484 (1995).10.1143/JPSJ.64.3484Google Scholar
3. Sidhu, P.S., Gilkes, R.J. and Posner, A.M., J. Inorg. Nucl. Chem. 40, 429 (1978).10.1016/0022-1902(78)80418-7Google Scholar
4. Ok, H.N., Pan, L.S. and Evans, B.J., Phys. Rev. B 17, 85 (1978).10.1103/PhysRevB.17.85Google Scholar
5. Dickof, P.A., Schurer, P.J. and Morrish, A.H., Phys. Rev. B 22, 115 (1980).10.1103/PhysRevB.22.115Google Scholar
6. Schwertmann, U. and Murad, E., Clay & Clay Minerals 38, 196 (1990).10.1346/CCMN.1990.0380211Google Scholar
7. Persoons, R.M., DeGrave, E. and Vandenberghe, R.E., Hyperfine Interact. 54, 655 (1990).10.1007/BF02396107Google Scholar
8. Hsu, P.H., J. Soil Sci. 23, 17 (1972).10.1111/j.1365-2389.1972.tb01637.xGoogle Scholar
9. Morup, S., Madsen, M.B., Franck, J., Villadsen, J. and Koch, C.J.W., J. Magn. Magn. Mater. 40, 163 (1983).10.1016/0304-8853(83)90024-0Google Scholar
10. Diamandescu, L., Mihaila-Tarabasanu, D., Calogero, S., Popescu-Pogrion, N. and Feder, M., Solid State Ionics, in press.Google Scholar
11. Giri, A.K., DeJulian, C. and Gonzales, J.M., J. Appl. Phys. 76, 6573 (1994).10.1063/1.358197Google Scholar