http://dyuthi.cusat.ac.in:80/xmlui/handle/purl/1826 2013-05-26T05:08:36Z 2013-05-26T05:08:36Z Reena Mary, A P Narayanan, T N Vijutha, Sunny Sakthikumar, D Yasuhiko, Yoshida Joy, P A Anantharaman, M R http://dyuthi.cusat.ac.in:80/xmlui/handle/purl/2964 2012-07-17T20:30:07Z 2010-01-01T00:00:00Z

Synthesis of Bio-Compatible SPION–based Aqueous Ferrofluids and Evaluation of RadioFrequency Power Loss for Magnetic Hyperthermia Reena Mary, A P; Narayanan, T N; Vijutha, Sunny; Sakthikumar, D; Yasuhiko, Yoshida; Joy, P A; Anantharaman, M R Bio-compatible magnetic fluids having high saturation magnetization find immense applications in various biomedical fields. Aqueous ferrofluids of superparamagnetic iron oxide nanoparticles with narrow size distribution, high shelf life and good stability is realized by controlled chemical co-precipitation process. The crystal structure is verified by X-ray diffraction technique. Particle sizes are evaluated by employing Transmission electron microscopy. Room temperature and low-temperature magnetic measurements were carried out with Superconducting Quantum Interference Device. The fluid exhibits good magnetic response even at very high dilution (6.28 mg/cc). This is an advantage for biomedical applications, since only a small amount of iron is to be metabolised by body organs. Magnetic field induced transmission measurements carried out at photon energy of diode laser (670 nm) exhibited excellent linear dichroism. Based on the structural and magnetic measurements, the power loss for the magnetic nanoparticles under study is evaluated over a range of radiofrequencies.

2010-01-01T00:00:00Z Swapna S, Nair Rajesh, S Abraham, V S Anantharaman, M R http://dyuthi.cusat.ac.in:80/xmlui/handle/purl/2844 2012-04-02T20:30:10Z 2011-04-01T00:00:00Z

Ferrofluid thin films as optical gaussmeters proposed for field and magnetic moment sensing Swapna S, Nair; Rajesh, S; Abraham, V S; Anantharaman, M R 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.

2011-04-01T00:00:00Z Senoy, Thomas Sakthikumar, D Yoshida, Yasuhiko Anantharaman, M R http://dyuthi.cusat.ac.in:80/xmlui/handle/purl/2843 2012-04-02T20:30:10Z 2008-01-01T00:00:00Z

Spectroscopic and photoluminescence studies on optically transparent magnetic nanocomposites based on sol–gel glass: Fe3O4 Senoy, Thomas; Sakthikumar, D; Yoshida, Yasuhiko; Anantharaman, M R Sol–gel glasses with Fe3O4 nanoparticles having particle sizes laying in the range 10–20 nm were encapsulated in the porous network of silica resulting in nanocomposites having both optical and magnetic properties. Spectroscopic and photoluminescence studies indicated that Fe3O4 nanocrystals are embedded in the silica matrix with no strong Si–O–Fe bonding. The composites exhibited a blue luminescence. The optical absorption edge of the composites red shifted with increasing concentration of Fe3O4 in the silica matrix. There is no obvious shift in the position of the luminescence peak with the concentration of Fe3O4 except that the intensity of the peak is decreased. The unique combinations of magnetic and optical properties are appealing for magneto–optical applications.

2008-01-01T00:00:00Z Hysen, Thomas Senoy, Thomas Ramanujan, R V Anantharaman, M R http://dyuthi.cusat.ac.in:80/xmlui/handle/purl/2842 2012-04-02T20:30:10Z 2008-01-01T00:00:00Z

On the crystallization kinetics and micro-structural transformations of Fe40Ni38B18Mo4 alloys Hysen, Thomas; Senoy, Thomas; Ramanujan, R V; Anantharaman, M R Activation energy for crystallization (Ec) is a pertinent parameter that decides the application potential of many metallic glasses and is proportional to the crystallization temperature. Higher crystallization temperatures are desirable for soft magnetic applications, while lower values for data storage purposes. In this investigation, from the heating rate dependence of peak crystallization temperature Tp, the Ec values have been evaluated by three different methods for metglas 2826 MB (Fe40Ni38B18Mo4) accurately. The Ec values are correlated with the morphological changes, and the structural evolution associated with annealing temperatures is discussed.

2008-01-01T00:00:00Z