Figure 3.

Visualization of the vector field of the magnetic forces between two spherical particles of nZVI, using software Mathematica 5, copyrighted by Wolfram Research, Inc. One nanoparticle is in an arbitrary point near a nanoparticle with radius a which is touching the center of the upper right side of the figure.

Rosick√° and ҆embera Nanoscale Res Lett 2011 6:10   doi:10.1007/s11671-010-9753-4