Magnetic properties of crystalline nanoparticles with different sizes and shapes

The effects of shape and finite size on the physical behavior of nanostructured antiferromagnetic particles are investigated. They were modeled as ellipsoidal systems which preserve the crystalline structure of the correspondent bulk material. In our analysis we consider nanoparticles composed by magnetic ions which are themselves insensitive to the presence of surfaces and/or interfaces. Results are shown for structures similar to MnF2 and NiO crystals. Special attention is given to these last once their singular magnetic arrangement, as well as, their use at different technological and/or biomedical applications, has motivated intense experimental studies at different laboratories. We use the parameters that describe the correspondent bulk material to discuss the magnetic behavior of these particles for different volumes and shapes.