Size Effect on Chemical Tuning of Spin−Lattice Relaxation Dynamics in Superparamagnetic Nanocrystals Academic Article uri icon

abstract

  • The size-dependent chemical tunability of spin-lattice relaxation rate in magnetic nanocrystals has been investigated in size and composition-controlled colloidal superparamagnetic CoxFe3-xO4 nanocrystals employing pump-probe Faraday rotation measurements. With the increase of cobalt content in CoxFe3-xO4 nanocrystals, spin-lattice relaxation rate increased due to the increasing spin-orbit coupling strength regardless of the particle size. However, the range of the chemical tunability of spin-lattice relaxation was narrower in the smaller nanocrystals and the size dependence of spin-lattice relaxation rate became weaker with increasing cobalt content. These observations were explained in terms of weaker chemical tunability of spin-orbit coupling on the surface than in the interior of the nanocrystals using a simple model for spin-lattice relaxation rate that has both surface and interior contributions. © 2010 American Chemical Society.

author list (cited authors)

  • Chen, T., Hsia, C., Chen, H., & Son, D. H.

citation count

  • 7

publication date

  • June 2010