Size-dependence of Magnetic Properties of Fe₃O₄ Nanoparticles for Medical Applications

Magnetic nanoparticles have potential as a contrasting agent for MRIs and a platform for cancer treatment and drug delivery. It is important to understand the magnetic properties of nanoparticles to predict how they will react in these applications. Previous research [1-3] showed that the magnetic behavior of magnetite nanoparticles varies with temperature. Above the blocking temperature, nanoparticles exhibit superparamagnetic behavior. Below, they enter the ‘blocked’ state and display hysteresis. This research further studies the size dependence of the superparamagnetic blocking transition using Vibrating Sample Magnetometry. Field cooling measurements are taken and analyzed to estimate the blocking temperature. Then, hysteresis loops are collected at set temperatures to measure the coercivity and magnetization at remanence. A summary of data from different samples is provided, with preliminary results depicting the correlation between nanoparticle size and these magnetic characteristics.

[1]Klomp et al. IEEE Transactions on Magnetics. 2020; 56(11):1–9.

[2]Chesnel et al. Magnetochemistry. 2018; 4(4):42.

[3]Rackham et al. Physical Review B. 2023; 103(104415)