Swapna, Nair S; Rajesh, S; Abraham, V S; Anantharaman, M R(Springer, April , 2011)
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Abstract:
Ferrofluids belonging to the series, Ni x Fe1-x Fe2O4 and Zn x Fe1-x Fe2O4, were synthesized using cold co-precipitation. Liquid films of these ferrofluids were prepared by encapsulating the ferrofluids in between two optically smooth and ultrasonically cleaned glass plates. Magnetic field induced laser transmission through these ferrofluid films has been investigated. Magnetic field values can be calibrated in terms of output laser power in the low field region in which the variation is linear. This set up can be used as a cheap optical gaussmeter in the low field regime. Using the same set-up, the saturation magnetization of the sample used can also be calculated with a sample that is pre-characterized. Hence both magnetization of the sample, as well as applied magnetic field can be sensed and calculated with a precalibrated sample.
Anantharaman, M R; Jagatheesan, S; Malini, K A; Sindhu, S; Narayanasamy, A; Chinnasamy, C N; Jacobs, J B; Reijne, S; Seshan, K; Smits, R H H; Brongersma, H H(Elsevier, April 14, 1998)
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Abstract:
Zinc ferrite belongs to the class of normal spinels where it is assumed to have a cation distribution of
Zn2`(Fe3`)2(O2~)4, and it is purported to be showing zero net magnetisation. However, there have been recent reports
suggesting that zinc ferrite exhibits anomaly in its magnetisation. Zinc ferrite samples have been prepared by two
di¤erent routes and have been analysed using low energy ion scattering, Mo¬ ssbauer spectroscopy and magnetic
measurements. The results indicate that zinc occupies octahedral sites, contrary to the earlier belief that zinc occupies
only the tetrahedral sites in a normal spinel. The amount of zinc on the B site increases with decrease in particle size. The
LEIS results together with the Mo¬ ssbauer results and the magnetic measurements lead to the conclusion that zinc
occupies the B site and the magnetisation exhibited by ultraÞne particles of zinc is due to short range ordering
Description:
Journal of Magnetism and Magnetic Materials 189 (1998) 83-88