Abstract
The structural, magnetic and electrical properties of the Al3+-substituted disordered spinel system Mg(Fe2−xAlx)O4 have been investigated by X-ray diffraction, magnetization, a.c. susceptibility and electrical resistivity measurements. The cation distribution derived from the X-ray diffractometry data was found to agree very well with the cation distribution obtained through Mössbauer spectroscopy. The variation of saturation magnetization per formula unit as a function of aluminium context, x, has been satisfactorily explained on the basis of Neel's collinear spin model and the slight discrepancy between the observed and calculated nB values can be explained in terms of a random canting model. The Néel temperatures calculated theoretically by applying molecular field theory agreed well with the experimentally determined values from thermal variation of susceptibility and electrical resistivity. An unusual metal-like thermo-electric behaviour was found for the compositions with x⩾ 0.3 which was attributed to the decrease in the Fe-Fe separation distance arising from aluminium substitution.
Article PDF
Similar content being viewed by others
Explore related subjects
Discover the latest articles, news and stories from top researchers in related subjects.Avoid common mistakes on your manuscript.
References
G. Blasse, Philips Res. Rep. Suppl. 3 (1964).
R. G.Kulkarni, and H. H.Joshi, id State Commun. 49 (1985) 1005.
R. V.Upadhyay and R. G.Kulkarni, 48(8) (1983) 69.
R. A.Brand, H.Georges-Gilbert, J.Hubsch and J. A.Heller, J. Phys. F Mater. Phys 15 (1985) 1987.
H.Knock and H.Dannheim, Phys. Status Solidi A 37 (1976) K 135.
E. De Grave, C.Dauve, A.Govaert and J. D.Sitter, Phys. Status Solidi B 73 (1967) 527.
U.Schmocaer, H. R.Boesch and F.Waidner, Phys. Lett. 40A (1972) 237.
K. V. S.Badarinath, Phys. Status. Solidi (a) K19 (1985) 639.
L. G. van Uitert, Proc. IRE October (1956) 1294.
M. D.Sundarajan, A.Narayanasamy, T.Nagarajan, L.Haggstron, C. S. Swamy and K. V.Ramanujachary, J. Phys. C Solid State Phys. 17 (1984) 2453.
Kunal B. Modi, H. H. Joshi and R. G. Eulkarni, id State Commun. submitted.
C.Radhakrishnamurty, S. D.Likhite and N. P.Sastry, Philos. Mag. 23 (1971) 503.
C.Radhakrishnamurty, S. D.Likhite and P. W.Sahastrabudhe, Proc. Ind. Acad. Sci. 87A (1978) 245.
C. G.Whinfrey, D. W.Eckart, A.Tauber, J. Am. Chem. Soc. 82 (1960) 2695.
“International Tables for the determination of Crystal structure”, Vol. 3 (Kynoch Press, Birmingham, 1968).
A.Rosencwaig, Cand. J. Phys. 48 (1970) 2857.
M. A.Gilleo, J. Phys. Chem. Solids 13 (1960) 33.
A. P.Nikolskii, Sov. Phys. Solid State 8 (1966) 960.
U. Varshney, R. J. Churchill, R. K. Puri and R. G. Mendoratta, in “Proceedings of the 5th International Conference on Ferrite”, Vol. 1, edited by C. M. Srivastava, Bombay, (1989) p. 255.
D. B.Rogers, J. L.Gilsa, T. E.Gier, id State Commun. 5 (1967) 143.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Modi, K.B., Joshi, H.H. & Kulkarni, R.G. Magnetic and electrical properties of Al3+-substituted MgFe2O4 . JOURNAL OF MATERIALS SCIENCE 31, 1311–1317 (1996). https://doi.org/10.1007/BF00353111
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/BF00353111