Controlling cooperative phenomena in nanomagnetic systems - New physics and its application:
The fundamental physics driven research programs of the Nanomagnetism Research Group will
make possible the next generation of devices and applications based on controlled magnetism
at the nanoscale by following three complementary themes.
One is to understand the surface, core and interaction properties of magnetic nanoparticles.
That is, magnetic metals and oxides with sizes 1-100 x 10-9 m that have
approximately 1020 fewer atoms then the average bulk magnetic sample.
Finite-size effects rule at these length scales. The second thrust area is to use nanoparticle
assemblies in amorphous and precisely ordered three dimensional lattice forms to design systems
that exhibit a collective state transition that would mark a fundamentally new regime with
nanoparticle properties no longer relevant to a thermally activated process. Central to both
of these research thrusts is nanoparticle sample synthesis and characterization. Our third research
thrust area is in thin-film magnetism (layers of magnetic materials that are a few to tens
of nanometers thick). Specifically, we study the magnetism that is the result of exchange coupling and
magnetic frustration at the interface of ferromagnetic and antiferromagnetic materials (exchange bias).
To develop a complete picture of nanoscale magnetism, one must probe across a range of time
and length scales. A consistent description must emerge from local and bulk magnetic
measurements. Simultaneously, the static and dynamic magnetic disorder must be decoupled.
To achieve this, we employ a wide variety of experimental techniques that measure magnetism
from the bulk to the atomic scale with time-scales that range from static to 10-13s.
Our collaborators are from the following universities, research laboratories and institutes: