In a recent study, which was published in the journal Nanotechnology, the groups used a focused ion beam as a nanowriter to modify the size and the density of an array of cobalt-platinum nanoparticles prepared via molecular beam deposition. This technique allows the researchers to fabricate assemblies of monodisperse nanoparticles with predictable magnetic properties.

Post-irradiation tuning

However, as with most nanoparticle fabrication techniques based on atom deposition methods, the size and density of particles are interdependent. José Penuelas and co-workers showed that the dispersion and morphology of as-grown self-organized nanoparticles can be tuned via the post-irradiation dose of a low-energy ion beam without changing the structure of the material.

The combined use of ultimate fabrication and patterning techniques provides a new way to obtain ultra small particles (in the 1–3 nm range) with tunable density. The main advantage of the focused ion beam approach is the ability to pattern the size and density of nanoparticles in a local way (over areas ranging from some tens of nanometres to several millimetres). These findings open the door to building new nanoscale model systems.

The results of the study have strong consequences for supported nanoparticle systems with properties that are related to feature size and interparticle spacing.