Swapna, Nair S; Rajesh, S; Abraham, V S; Anantharaman, M R(Springer, April , 2011)
[+]
[-]
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; Nampoori, V P N; Abraham, V S; Rajesh, S; Swapna, Nair S(Elsevier, December 27, 2005)
[+]
[-]
Abstract:
Fine magnetic particles (sizeffi100A ˚ ) belonging to the series ZnxFe1 xFe2O4 were synthesized by cold co-precipitation methods and
their structural properties were evaluated using X-ray diffraction. Magnetization studies have been carried out using vibrating sample
magnetometry (VSM) showing near-zero loss loop characteristics. Ferrofluids were then prepared employing these fine magnetic powders
using oleic acid as surfactant and kerosene as carrier liquid by modifying the usually reported synthesis technique in order to induce
anisotropy and enhance the magneto-optical signals. Liquid thin films of these fluids were prepared and field-induced laser transmission
through these films was studied. The transmitted light intensity decreases at the centre with applied magnetic field in a linear fashion
when subjected to low magnetic fields and saturate at higher fields. This is in accordance with the saturation in cluster formation. The
pattern exhibited by these films in the presence of different magnetic fields was observed with the help of a CCD camera and was
recorded photographically
Description:
Journal of Magnetism and Magnetic Materials 305 (2006) 28–34