Magnetic nanoparticles are known to have very interesting properties both in zero-field and in an applied magnetic field. Interestingly, they form these unique structures known as chains when subject to a strong-enough magnetic field. This effect can be detrimental to several applications of magnetic nanoparticles including their use in MRI as contrast agents as carriers for drug delivery. Chaining, its effects on applications and its prevention are aspects that I’m exploring in my PhD.

Pictured below are 2 long chains of magnetic nanoparticles that appear to be in the process of forming a large 12 micron super-chain. The individual chains themselves appear to be composed of smaller units, suggesting how chains evolve over time.

Magnetic nanoparticles chaining in an applied magnetic field