The group from Cochin University and the Raman Research Institute, both in India, and Rice University, US, has reported that metallic magnetic ferrofluids of nickel in kerosene carrier fluid exhibit high non-linear optical limiting along with magnetic field dependent linear transmission.

The oxide free Ni nanofluid is synthesized by a versatile route where ultrafine Ni nanoparticles are suspended in kerosene with high shelf-life and stability. The constituent particles align in an external magnetic field and become suddenly randomized when the field is removed retaining their fluid nature.

More details are available in the journal Nanotechnology.