Time-resolved study of surface spin effect on spin-lattice relaxation in Fe3O4 nanocrystals. Academic Article uri icon

abstract

  • The role of surface spins in the relaxation of magnetization in optically excited Fe(3)O(4) nanocrystals has been investigated via time-resolved Faraday rotation measurements. The time scale of the magnetization recovery following the optically induced demagnetization increased from 250 to 350 ps as the size of the nanocrystals increased from 5 to 15 nm. From analysis of the data with a simple model relating the spin-lattice relaxation rate to the average spin-orbit coupling strength of the interior and surface spins, we estimated the relative efficiency of surface in spin-lattice relaxation with respect to the interior spins. Our analysis indicates that, in Fe(3)O(4) nanocrystals passivated with oleic acid, the surface is 3 times more efficient in spin-lattice relaxation than the interior.

published proceedings

  • J Am Chem Soc

author list (cited authors)

  • Hsia, C., Chen, T., & Son, D. H.

citation count

  • 14

complete list of authors

  • Hsia, Chih-Hao||Chen, Tai-Yen||Son, Dong Hee

publication date

  • June 2009