© 2018 IJRAR January 2019, Volume 6, Issue 1 www.ijrar.org (E-ISSN 2348-1269, P- ISSN 2349-5138) IJRAR19J1612 International Journal of Research and Analytical Reviews (IJRAR) www.ijrar.org 1058 SUPERPARAMAGNETIC Fe-Mn FERRITE NANOPARTICLES FOR MAGNETIC FLUID HYPERTHERMIA Jyoti Dhumal a , S. S. Bandgar a , Manisha Phadatare b and G. S. Shahane a* a Department of Electronics, DBF Dayanand College of Arts and Science, Solapur, MS, India b Department of Medical Physics, Centre for Interdisciplinary Research, D. Y. Patil Education Society, (Deemed University) Kolhapur, MS, India. Abstract: The structural, magnetic and ac magnetically induced heating characteristics of citric acid coated nanoferrites having composition Fe1-xMnxFe2O4 (x = 0.0, 0.1, 0.3, 0.5, 0.7, 0.9 and 1.0) have been investigated. The XRD patterns confirm the synthesis of single crystalline phase of Fe-Mn ferrite nanoparticles. Substitution of Mn 2+ in Fe3O4 causes an increase in the lattice constant from 8.335 to 8.448 Å. The average crystallite size ranges from 9 to 11 nm. The particle sizes observed from TEM analysis are in good agreement with the XRD values. The magnetic measurements show superparamagnetic nature of the samples. The saturation magnetization increases with increase in Mn-concentration, reaches maximum for x=0.7 and decreases further for further increase in the value of x. The variation in saturation magnetization can be correlated to the modifications in cation distribution as a result of replacement of Fe 2+ ions (μ B=4) by Mn 2+ ions (μ B=5) thereby modifying the superexchange interaction between the A and B sublattices. The induction heating studies of these nanoparticles at different alternating magnetic fields operating at frequency 289 kHz were carried out by dispersing nanoparticles in DDW. The SAR exhibits similar variation as saturation magnetization. It is observed that the value of SAR increased by 20% in Fe0.3Mn0.7Fe2O4 as compared to Fe3O4. The superparamagnetic nature, narrow size distribution and enhanced SAR make these nanoparticles a promising candidate for hyperthermia applications. Keywords: Fe-Mn nanoferrites, Structural characterization, Magnetic properties, Hyperthermia. I. INTRODUCTION Magnetic nanoparticles of transition metal ferrites are of great interest for their properties, which are novel in comparison with the corresponding bulk materials. The ferrite nanoparticles in nano-sized form are useful for a variety of applications such as high-density information storage devices, microwave devices, transformer cores and biomedical applications such as targeted drug delivery, magnetic resonance imaging, hyperthermia, enzyme immobilization, etc. [1,2]. Magnetic hyperthermia using ferrite nanoparticles has recently emerged as a promising therapeutic approach for cancer treatment. In magnetic hyperthermia, magnetic nanoparticles are used to raise the temperature of a region of the body affected by cancer to 42-46 °C via absorption of radio frequency when subjected to an alternating current (ac) magnetic field. This method involves the introduction of ferromagnetic nanoparticles into tissues, and their subsequent irradiation with an alternating electromagnetic field [3,4]. In spite of enormous efforts in this field, clinical appliances of hyperthermia for completely treating cancer were not effective. High heating temperatures and large specific absorption rate (SAR) at small particle concentration are considered as most critical challenge to achieve desirable tumor damage. The challenging work is the development of magnetic nanoparticles (heating mediator) with high specific absorption rate (SAR), which allows reduction of ferrofluid dose in vivo. SAR depends on several parameters like particles magnetization, size and distributions, AC magnetic field and frequencies [5]. For biomedical applications, iron oxide nanoparticles are the primary choice because of their biocompatibility, superparamagnetic behavior and chemical stability. Numbers of reports are available on the application of Fe3O4 nanoparticles for hyperthermia [6,7]. Substituted ferrite systems Fe1-xBxFe2O4 (B = Mn, Co) where certain degree of substitution of Fe (II) ions by other divalent ions (Mn or Co) can increase the magnetic moment. Thus, it is expected that these substituted ferrite particles have versatile spin–spin relaxation time depending on their compositions [8]. As an important member of the ferrite family, MnFe2O4 (MFO) has attracted noteworthy research interest due to its mesmerizing magnetic and electromagnetic properties [9]. It is reported that substitution of Mn does not cause change in viability rates of HeLa cells as compared to Fe3O4 which is already known to be biocompatible [10]. It is well known that both Fe3O4 and MnFe2O4 materials have inverse spinel structure showing ferrimagnetism that originates from magnetic moment of antiparallel spins between Fe 3+ ions at A-sites and Fe 2+ /Mn 2+ and Fe 3+ ions at B-sites. Thus, one can aim at tuning the saturation magnetization value of Fe-Mn ferrite