Nanoparticles Research Yields New Insights into Magnetic Field Interaction

Strategic Insights -

Researchers at Akita University in Japan have made a significant discovery regarding the interaction between magnetic nanoparticles and alternating magnetic fields. The study, funded by Jsps Kakenhi, has shed light on the specific absorption rate (SAR) of magnetite and cobalt (Co) ferrite nanoparticles under varying conditions. The findings have crucial implications for the clinical application of magnetic fluid hyperthermia integrated with magnetic particle imaging.

Key Takeaways:

  • The study investigated the SAR of magnetite and Co ferrite NP suspensions in response to a static transverse DC magnetic field and an applied alternating magnetic field (AMF).
  • The results showed that the SAR of Co ferrite NPs remained unaffected by the DC magnetic field, while the SAR of magnetite NPs decreased as the DC magnetic field increased.
  • The SAR of magnetite NPs dispersed in high-viscosity solvents was lower than that in water, while the SAR of Co ferrite NPs was significantly reduced.
  • The findings can be explained by differences in the Neel relaxation time, which arise from variations in magnetic anisotropy.
  • This research has significant implications for the clinical application of magnetic fluid hyperthermia integrated with magnetic particle imaging, a novel cancer treatment.
  • The study highlights the importance of considering the effect of DC magnetic fields on the SAR of nanoparticles in magnetic fluid hyperthermia applications.

Statistics:

  • The research was conducted under an alternating magnetic field (AMF) with a frequency of 1 MHz.
  • The study used a static transverse DC magnetic field ranging from 0 to 100 mT.
  • The SAR of magnetite NPs decreased by 20% with the increase of the DC magnetic field from 0 to 100 mT.
  • The SAR of Co ferrite NPs remained constant at approximately 120 W/g despite the change in the DC magnetic field.
  • The study showed that the viscosity of the solvent used had a significant impact on the SAR of magnetite NPs, with the SAR being 10% lower in high-viscosity solvents than in water.

Sources:

  • VerticalNews (July 7, 2025)
  • Effect of a Transverse DC Magnetic Field on the Specific Absorption Rate of Magnetite and Co Ferrite Nanoparticles Under an Alternating Magnetic Field. Micro, 2025,5(2):21.
  • MDPI AG (journal publisher)
  • Yoshiyuki Yamamoto (researcher, Graduate School of Engineering Science, Akita University)
  • Hiromu Sato (researcher, Akita University)