# Superparamagnetic Fe/Au Nanoparticles and Their Feasibility for Magnetic Hyperthermia
## 4 Conclusions  
Fe/Au core/shell nanoparticles have been successfully synthesized using a wet chemistry method at ambient conditions and have been investigated with respect to their structural and magnetic properties. Our SEM and TEM studies show that gold coated nanoparticles with Fe core are formed (a core/shell structure) with a size distribution from few tens nanometers. The as-prepared nanoparticles show Fe/Au with a spherical- shape and an average size of 71 nm. X-ray diffraction was applied to confirm the phase of the core material. The size of the core particles has been deduced from the width of the XRD peaks. XRD patterns confirm the formation of pure Fe core for the 2:1 Fe:Au sample and mixture of Fe and magnetite core for the other 1:1 and 3:2 Fe:Au samples. The magnetic properties revealed superparamagnetic-like behavior for the 2:1 Fe:Au sample with high saturation magnetization at room temperature and mixture of superparamagnetic and ferromagnetic behaviors for the other 1:1 and 3:2 Fe:Au ratios. The feasibility of hyperthermia was measured for the dispersed nanoparticles in water solution, yielding good heating power showing the potential of the Fe/Au nanoparticles for hyperthermia treatment of cancer. To be specific, the samples were dispersed in water with concentration of 5 mg/mL and the heating power was recorded under applied magnetic fields and frequencies. SAR values were measured at the therapeutic range of 400 Oe and 304 kHz to yield 35, 50, 25 W/g for  
Figure 4: The effect of changing applied A.C. magnetic fields (H) at different frequencies \(f\) for samples with morphological sizes 61, 71, 83 nm on (**A**) the temperature and (**B**) S.A.R.  
synthesized samples at Fe:Au precursor's ratio of 1:1, 2:1, 3:2, respectively. The study open new route for using Fe/Au nanoparticles as a good inducing heat mediator for invitro and invivo magnetic nanoparticle hyperthermia studies for cancer treatment in the future.  
The following are available online at [[https://www.mdpi.com/article/10.390/app11146637/s1](https://www.mdpi.com/article/10.390/app11146637/s1)]([https://www.mdpi.com/article/10.390/app11146637/s1](https://www.mdpi.com/article/10.390/app11146637/s1)), Table S1: Comparison of coercivity and saturation magnetization with literatures.  
[PERSON] performed the synthesis experiments under the supervision and guidance of [PERSON] and wrote the synthesis part of the manuscript. [PERSON] did the characterization measurements including XRD, SEM, VSM, and hyperthermia and wrote the hyperthermia part. [PERSON] helped [PERSON] and [PERSON] in the characterization analysis and writing of the manuscript. [PERSON] and [PERSON] have performed the TEM analysis and revised the manuscript. [PERSON] designed the idea, supervised, discussed the results with the co-authors, revised and edited the manuscript. All authors have read and agreed to the published version of the manuscript.  
This research was funded by US-National Science Foundation, grant number 2009358 and by National Institutes of Health, grant number RL5 GM118969, TL4 GM118971, and ULIGM118970.  
Not applicable.  
[PERSON] acknowledges the startup and rising stars funds by U.T.E.P. and UT-system, respectively.  
The authors declare no conflict of interest.