[01] Jyoti Dhumal, Department of Electronics, DBF Dayanand College of Arts & Science, Solapur, Maharashtra, India. [02] Sushilkumar Bandgar, Department of Electronics, DBF Dayanand College of Arts & Science, Solapur, Maharashtra, India. [03] Kisan Zipare, Department of Electronics, DBF Dayanand College of Arts & Science, Solapur, Maharashtra, India. [04] Guruling Shahane, Department of Electronics, DBF Dayanand College of Arts & Science, Solapur, Maharashtra, India.

Nanocrystalline Fe₃O₄ particles of controlled size were synthesized by a facile chemical co-precipitation method. The X-ray diffraction patterns confirm the synthesis of single crystalline phase of Fe₃O₄ nanoparticles with lattice parameter 8.4090 Å. The average particle size of as-synthesized sample is 11.5 nm. A TEM analysis show that the sample contains well dispersed nanoparticles of almost spherical in shape with average particle size is of the order of 10-20 nm. The magnetic measurements show superparamagnetic nature of the sample. The saturation magnetization is 63emu/g. The rheological study of oleic acid coated Fe₃O₄ ferrofluid show magneto-viscous effect. In the absence of the magnetic field, the ferrofluids behave essentially as a Newtonian fluid having a rate-insensitive viscosity whereas increase in the magnetic field leads to strong changes in the viscosity. This can be attributed to the formation of chain-like clusters due to strong inter-particle interaction in the presence of a magnetic field.

Fe₃O₄ Nanoparticles, Structural Characterization, Magnetic Properties, Ferrofluid

[01] W. Brullot, N. K. Reddy, J. Wouters, V. K. Valev, B. Goderis, J. Vermant and T. Verbiest, J. Magn. Magn Mater., 324 (2012) 1919. [02] J. P. Dery, E. F. Borra, A. M. Ritcey, Chemistry of Materials, 20 (2008) 6420. [03] C. L. Sansom, P. Jones, R. A. Dorey, C. Beck, A. Stanhope-Bosumpim and J. Peterson, J. Magn. Magn. Mater, 335 (2013) 159. [04] R. Patel, K. Parekh, R. V. Upadhyay and R. V. Mehta, Ind. J. Engin. & Mater. Sci., 11 (2004) 301. [05] V. Kumar, R. P. Pant, S. K. Haldar, M. S. Yadav, Ind. J. Pure & Appl. Phys., 45 (2007) 406. [06] O. P. Nautiyal, S. C. Bhatt, Magnetohydrodynamics, 49 (3-4) (2013) 484. [07] S. Palacin, P. C. Hidber, J. Bourgoin, C. Miramond, C. Fermon, and G. Whitesides, Chem. Mater. 8 (1996) 1316. [08] L. M. Yu, S. X. Cao, Y. S. Liu, J. J. Wang, J. C. Zang, J. Magn. Magn. Mater, 301 (2006) 100. [09] J. Giri, T. Sriharsha, S. Asthana, T. K. G. Rao, A. K. Nigam and D. Bahadur, J. Magn. Magn. Mater, 293 (2005) 55. [10] A. Rana, O. P. Thakur and Vinod Kumar, Mater. Lett, 65 (2011) 3191. [11] K. V. P. M. Shafi, A. Gedanken, R. Prozorov, and J. Balogh, Chem. Mater.,10 (1998) 3445. [12] D. J. Fatemi, V. G. Harris, V. M. Browning, and J. P. Kirkland, J. Appl. Phys., 83 (1998) 6867. [13] G. S. Shahane, Ashok Kumar, M. Arora, R. P. Pant and K. Lal, J. Magn. Magn. Mater, 322 (2010) 1015. [14] M. Chand, A. Shankar, Noorjahan, K. Jain, R. P. Pant, RSC Adv. 4 (2014) 53960. [15] H. Shahnazian and S. Odenbach, J. Phys.: Condens. Matter, 20 (2008) 204137. [16] K. Parekh, R. V. Upadhyay, R.V. Mehta, Hyperfine Interactions, 160 (2005) 211. [17] M. Chand, S. Kumar, A. Shankar, R. Porwal and R. P. Pant, J. Non-Cryst. Solids, 361 (2013) 38. [18] E. M. Rarani, N. Etesami, N. Esfahany, J. Appl. Phys., 112 (2012) 094903. [19] S. Wu, A. Sun, F. Zhai, J. Wang, W. Xu, Q. Zhang, A. A. Volinsky, Mat. Lett, 65 (2011) 1882. [20] A. Shankar, S. Kumar, S. Thakur, R. Porwal and R. P. Pant, Adv. Mat. Lett. 3(5) (2012) 415. [21] J. Sun, S. Zhou, P. Hou, Y. Yang, J. Weng, X. Li, M. Li, J. Biom. Mater. Res. Part A DOI 10.1002/jbm.a (2006) 333. [22] K. H. Wu, T. H. Ting, G.P. Wang, C. C. Yang and B.R. Mc Garvey, Mater. Res. Bull. 40 (2005) 2080. [23] B. P. Rao, A. Maheshkumar, K. H. Rao, Y. L. N. Murthy and O. F. Caltun, J. Optoelectr. Adv. Mater. 8 (2006) 1703.