Synthesis of Zn, Mn doped Fe₃O₄ Nanoparticles with Tunable Size

Zn, Mn doped Fe₃O₄ magnetic nanoparticles have broad application prospects in biomedicine for their excellent magnetic properties. Therein, the most remarkable property of magnetic nanoparticles is size-dependent biomagnetic applications, and size variation also affect their magnetic characteristics. Therefore, based on the specific requirements of size for various biological applications, it is critical to regulate their size. In this study, we synthesized 5-20 nm Zn, Mn doped Fe₃O₄ magnetic nanoparticles by changing reflux time duration, varying metal precursor and adding oil phase reducing agent (1,2-hexadecanediol). It is found that addition of 1,2-hexadecanediol is beneficial to the formation of smaller nanoparticles, while metal chloride and longer reflux time are helpful to prepare larger particles. Additionally, there exists a positive correlation between particle size and saturation magnetization.