Biomedical applications of nano-sized magnetic materials

Abdelhamid, Ehab H. A.

Allyn, Megan

Garg, Vijayendra K.

Tackett, Ronald

Vaishnava, Prem

English

Kettering University

Kettering UniversityDigital Commons @ Kettering UniversityPhysics Presentations And Conference Materials Physics3-2016A comparison of methods for the determination ofthe magnetocrystalline anisotrophy constant in anFe3O4-based ferrofluidRonald TackettKettering UniversityMegan AllynKettering UniversityVijayendra K. GargUniversity of BrasíliaEhab H. A. AbdelhamidWayne State UniversityPrem VaishnavaKettering UniversityFollow this and additional works at: https://digitalcommons.kettering.edu/physics_conferencePart of the Physics CommonsThis Presentation is brought to you for free and open access by the Physics at Digital Commons @ Kettering University. It has been accepted forinclusion in Physics Presentations And Conference Materials by an authorized administrator of Digital Commons @ Kettering University. For moreinformation, please contact digitalcommons@kettering.edu.Recommended CitationTackett, Ronald; Allyn, Megan; Garg, Vijayendra K.; Abdelhamid, Ehab H. A.; and Vaishnava, Prem, "A comparison of methods for thedetermination of the magnetocrystalline anisotrophy constant in an Fe3O4-based ferrofluid" (2016). Physics Presentations AndConference Materials. 9.https://digitalcommons.kettering.edu/physics_conference/9A comparison of methods for the determination of the magnetocrystalline anisotropy constant in an Fe3O4-based ferrofluid.R.J. Tackett1, M.M. Allyn2, V.K. Garg3, A.C. de Oliveira3, E.A. Elhamid4 and P.P. Vaishnava11Department of Physics, Kettering University, Flint, MI 485042Department of Chemical Engineering, Kettering University, Flint, MI 485043Institute of Physics, University of Brasilia, Brazil 70910-9004Department of Physics Wayne State University, Detroit, MI 48201Nano-sized magnetic materials display physical and chemical properties which may bequite different from those of their bulk counterparts and have important technologicaland biomedical applications.PhysicsChemistry BiologyBiomedicineInformation StorageImagingIn order to compare the performance of these magnetic nanoparticles, their magneticproperties such as saturation magnetization, magnetocrystalline anisotropy, blockingtemperature, and Curie temperature need to be studied in detail.Properties of Magnetic NanoparticlesBlocking TemperatureCurie TemperatureSaturation MagnetizationMagnetocrstallineAnisotropyAddNH4OH(under N2)until pH 10Decant and Rinse MNPsFeCl3∙6H2O+HCl (aq)FeCl2∙4H2O+HCl (aq)Iron-oxide (Fe3O4) nanoparticles were synthesized using a co-precipitation technique andcoated with dextran in order to prevent agglomeration and to allow suspension in water.Xu et al. (2005) App. Surface Sci. 252, 494-500Powder x-ray diffraction and transmission electron microscopy wereused to characterize the samples.𝐷𝑎𝑣𝑔 = 13.7 ± 4.7 nmA fit of the room temperature 𝑀 𝐻 data to a Langevin function wasused in order to determine the magnetic size of the nanoparticles.0.0 2.5 5.0 7.5 10.00102030M(emu/g)H (kOe)0.0 2.5 5.0 7.5 10.00102030M(emu/g)H (kOe)𝐷𝑚𝑎𝑔 = 9.8 ± 4.6 𝑛𝑚𝑀 𝐻 = 𝑀𝑠0׬∞𝑓 𝑑 𝑉ℒ 𝑥 𝑑𝐷0׬∞𝑓 𝑑 𝑉𝑑𝐷𝑥 =𝑀𝑠𝑉𝐻𝑘𝐵𝑇ℒ 𝑥 = coth 𝑥 −1𝑥𝑓 𝐷 =12𝜋𝜎𝐷exp −ln 𝐷/𝐷022𝜎2Using the frequency dependence of the blocking temperature as measured using the acmagnetic susceptibility allows us to calculate the magnetocrystalline anisotropyconstant.𝐾 = 54.4 ± 15.3 kJ/m3100 150 200 250 300234 300 Hz 1.0 kHz 3.0 kHz 10 kHz'' (arb. units)T (K)0.0052 0.0056 0.0060 0.0064-10-9-8-7-6-5-4ln  1/Tp (K-1)0 ~ 10-10 sEA ~ 2700 K𝜏 = 𝜏0exp −𝐾𝑉𝑘𝐵𝑇𝐸𝐴 = 𝐾𝑉Using the room temperature hyperfine field and the zero Kelvin hyperfine fielddetermined via Mössbauer spectroscopy allows us to calculate the magnetocrystallineanisotropy constant.-10 -5 0 5 105.585.605.625.645.66  Data FitAbsorption (106 counts)v (mm/s)𝐵𝐻𝐹 𝑅𝑇 = 480 kOe𝐵𝐻𝐹 𝑅𝑇𝐵𝐻𝐹 0K= (1 − 𝑘𝐵𝑇/2𝐾𝑉)𝐵𝐻𝐹 0K = 517 kOe𝐾 = 55.7 ± 45.6 kJ/m3Using the room temperature hyperfine field and the zero Kelvin hyperfine fielddetermined via Mössbauer spectroscopy allows us to calculate the magnetocrystallineanisotropy constant.0 50 100 150170180190200210DCBT (K)t (s)AA - 343 kHzB - 232 kHzC - 171 kHzD - Ambient170 180 190 200 2104.04.55.05.56.0 f1 = 171 kHz     f2 = 232 kHzf1 = 171 kHz     f2 = 343 kHz f1 = 232 kHz     f2 = 343 kHz N (10-7 s)T (K) 121 222121 ffffN2121fambientmagneticfambientmagneticfftTtTtTtTSARSAR𝐾 = 40 ± 28 kJ/m3 𝜏 = 𝜏0exp −𝐸𝐴𝑘𝐵𝑇Finally, we compare the magnetocrystalline anisotropy constants as determined fromthree different experimental methods.Method K (kJ/m3)AC Magnetic Susceptibility 18.7 ± 15.3Mössbauer Spectroscopy 55.7 ± 45.6Hyperthermia Measurements 40 ± 28

A comparison of methods for the determination of the magnetocrystalline anisotrophy constant in an Fe3O4-based ferrofluid

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A comparison of methods for the determination of the magnetocrystalline anisotrophy constant in an Fe3O4-based ferrofluid

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