Abstract:

Computer simulations are presented to explore the magnetic and magnetomechanical properties of hollow microspheres consisting of a self-supporting shell of iron-oxide nanoparticles which were recently synthesized in experiment. The magnetic properties of the microspheres are governed by the dipolar interactions between the nanoparticles, leading to a complex vortex ground state structure with the magnetic moments aligned parallel to the surface. In magnetic fields, considerable deformations are observed that withstand external applied pressures.