tailieunhanh - Influence of saturation magnetization and viscosity on specific loss power for CoFe2O4 and MnFe2O4 magnetic nanoparticles

Magnetic nanoparticles absorb energy from external alternating magnetic field to create a nanosized heating source. Specific loss power (SLP) is affected strongly by several magnetic parameters of material and viscosity of nanofluid. In this study, the specific loss power as dependent on saturation magnetization was calculated for hard ferrite CoFe2O4 (K = 290 kJ/m3 ) and soft ferrite MnFe2O4 (K = 3 kJ/m3 ) with two values of viscosity in biological range 1-2 mPas. | Journal of Science and Technology 54 (1A) (2016) 33-41 INFLUENCE OF SATURATION MAGNETIZATION AND VISCOSITY ON SPECIFIC LOSS POWER FOR CoFe2O4 AND MnFe2O4 MAGNETIC NANOPARTICLES Luu Huu Nguyen1, 2, *, Phan Quoc Thong1, 2,, Pham Hong Nam2, Le Thi Hong Phong2, Pham Thanh Phong1, Nguyen Xuan Phuc2 1 University of Khanh Hoa, 01 Nguyen Chanh Road, Nha Trang, Khanh Hoa Institute of Materials Science, VAST, 18 Hoang Quoc Viet Road, Cau Giay, Ha Noi 2 * Email: lhnohh2@ Received: 30 August 2015; Accepted for publication: 25 October 2015 ABSTRACT Magnetic nanoparticles absorb energy from external alternating magnetic field to create a nanosized heating source. Specific loss power (SLP) is affected strongly by several magnetic parameters of material and viscosity of nanofluid. In this study, the specific loss power as dependent on saturation magnetization was calculated for hard ferrite CoFe2O4 (K = 290 kJ/m3) and soft ferrite MnFe2O4 (K = 3 kJ/m3) with two values of viscosity in biological range 1-2 mPas. Besides, we investigated the experimental dependence SLP on their saturation magnetization while changing viscosity using agar powder. A large change of slope SLP was found for CFO Ms when the viscosity changes; whereas it remained almost unaffected by the variation of viscosity fluid of MFO. All calculation and experimental results are discussed via the competition between Néel and Brown relaxation. Keywords: Neel-Brown relaxation, saturation magnetization, specific loss power, viscosity. 1. INTRODUCTION Magnetic nanoparticles (MNPs) have recently been the subject of intensive study of both basic research and applications; especially in biomedicine and biotechnology [1 - 6]. Magnetic Inductive Heating (MIH) is the phenomenon that MNPs adsorb energy from external alternating magnetic field (AMF) to create a heating source that can be used as thermo seed in ‘killing’ cancer cells in hyperthermia [2, 5 - 7]. The so-called specific loss power (SLP) is commonly