Magnetic field induced chaining of magnetic nanoparticles and its effects on proton relaxation rates

R.R. Varsani, K.S. Iyer, R.C. Woodward, M.J. House, T.G. St Pierre, M. Saunders
The University of Western Australia, AU

Keywords: magnetic nanoparticles, chaining, relaxation rates, MRI, dipolar chains

Summary:

Magnetic nanomaterials are an interesting and promising class of materials with applications in data storage and biomedicine. Magnetic nanoparticles suspended in a fluid and exposed to a magnetic field have been known to form linear chains along the direction of the magnetic field. Although there have been many theoretical studies on the change in magnetic properties of chaining magnetic nanoparticles, there has been insufficient experimental evidence for this. This work aims to address this by measuring the time-varying relaxation rates of protons in the fluid suspending the magnetic nanoparticles in a magnetic field and correlating them to their macrostructure by locking the particles in agarose and resin while still in the magnetic field.