Core-shell magnetic morphology of structurally uniform magnetite nanoparticles

Phys Rev Lett. 2010 May 21;104(20):207203. doi: 10.1103/PhysRevLett.104.207203. Epub 2010 May 19.

Abstract

A new development in small-angle neutron scattering with polarization analysis allows us to directly extract the average spatial distributions of magnetic moments and their correlations with three-dimensional directional sensitivity in any magnetic field. Applied to a collection of spherical magnetite nanoparticles 9.0 nm in diameter, this enhanced method reveals uniformly canted, magnetically active shells in a nominally saturating field of 1.2 T. The shell thickness depends on temperature, and it disappears altogether when the external field is removed, confirming that these canted nanoparticle shells are magnetic, rather than structural, in origin.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Magnetics*
  • Magnetite Nanoparticles / chemistry*
  • Neutron Diffraction
  • Scattering, Small Angle
  • Temperature

Substances

  • Magnetite Nanoparticles