Magnetic Heating Properties of Hollow Fe3O4 Nanoparticles with Magnetic Vortex Structure

• Published in: Transaction of the Magnetics Society of Japan Special Issues Vol. 8; no. 2; pp. 79 - 83
• Main Authors: Tonthat, L., Yabukami, S., Akiyama, H., Kuwahata, A., Kobayashi, S.
• Format: Journal Article
• Language: Japanese
• Published: The Magnetics Society of Japan 01.09.2024; 公益社団法人 日本磁気学会
• Subjects: heating efficiency; hollow Fe3O4 nanoparticles; magnetic hyperthermia; magnetic vortex structure
• ISSN: 2432-0471
• DOI: 10.20819/msjtmsj.24TR816

  Hollow-structured Fe3O4 nanoparticles, with an increased surface area compared to solid counterparts, show promise in cancer therapy through potential applications in magnetic hyperthermia and drug delivery via encapsulation. This study investigates the shell thickness-dependent heating efficiency of hollow Fe3O4 nanoparticles with a magnetic vortex structure less prone to magnetization reversal. Using the solvothermal method, we maintained a nearly constant inner diameter (230 nm) while varying shell thickness (400 nm, 530 nm, and 720 nm in outer diameter denoted as H400, H530, and H720) by adjusting only the outer diameter through a change in reagent ratio and heating temperature. Under an applied AC magnetic field of 270 kHz, 429.5 Oe, the specific absorption rate (SAR) values of H400, H530, and H720 samples (calculated based on the initial temperature rising rate observed during the time interval of 0 to 30s) were 265.1, 130.2, and 120.9 W/g, respectively. These findings, supported by DC hysteresis loss experiments and micromagnetic simulations of AC hysteresis loss, indicate that particles with thinner shells at the same inner diameter exhibit enhanced heating efficiency due to a stable magnetic vortex structure and significant hysteresis loss. This highlights the potential utility of hollow nanoparticles with thin shells as a particle shape for magnetic hyperthermia.