Nov 25, 2011
Metallic ferrofluids show optical limiting
Good optical limiting materials are in demand for photonic devices and controlling their behaviour by an external stimulus such as an electric or magnetic field is of great technological interest. Researchers based in India and the US have teamed up to investigate nickel nanofluids for device applications such as optical switches and magneto-controlled optical limiters.
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.
About the author
A P Reena Mary is a PhD scholar in the Magnetics Lab at Cochin University of Science and Technology (CUSAT) under the guidance of Prof. M R Anantharaman, professor and head of the Department of Physics at CUSAT. This group has been actively involved in ferrofluid research. C S Suchand Sandeep has graduated from the Raman Research Institute, Bangalore under Prof. Reji Philip and is now pursuing postdoctoral studies at TU Delft, the Netherlands. T N Narayanan is a graduate from CUSAT and is a postdoctoral research associate in the Mechanical Engineering and Materials Science department at Rice University, US, and Padraig Moloney is a graduate student in the same department. P M Ajayan is the Benjamin M and Mary Greenwood Anderson Professor of Engineering in the Mechanical Engineering and Materials Science department at Rice University, US.