25.05.2011 -
1904: the number for the world record in the measurement of
tunnelling magnetoresistance (TMR) achieved in Trieste; a frontier
of knowledge that could revolutionise computer memory performance
or enable the creation of microsensors that are considerably more
sensitive than, for example, those currently used in car ABS
systems.
This is the science of spintronics, a combination of electronics
and magnetism, whose development is closely linked to research on
new materials, their configuration and the engineering process
within the vast field of nanotechnology. A multidisciplinary field
that requires considerably advanced techno-scientific expertise and
state-of-the-art equipment, both of which are available at the
Istituto Officina dei Materiali - CNR at AREA Science Park in
Trieste.
Success was achieved as a result of the SPINOX project. Here
researchers managed to manipulate, with the utmost precision and on
an atomic level, a combination of titanium, manganese, strontium
and lanthanum, creating a nanostructured configuration so close to
theoretical models that they were able to produce magnetoresistance
levels in the laboratory that had never before been attained.
Magnetoresistance is the property of a material to change the
value of its electrical resistance when an external magnetic field
is applied. The higher the magnetoresistance, the greater the
possibility for creating more reliable and more energy-efficient
microprocessors as well as new generations of magnetic field
sensors for use in safety systems.
Bruce Davidson is the coordinator of SPINOX and a rare example
of a researcher who moved from the United States to Italy,
attracted by the quality of the scientific work being performed in
Trieste. "In spintronics," explains Davidson, "we use, in addition
to the electric charge of the electron, the magnetic field - or
spin - creating the conditions needed to produce miniaturised
instruments with better performance and lower consumption.
Spintronics is a very recent approach but has already had an
enormous technical and economic impact thanks to the use of giant
magnetoresistance (GMR); this phenomenon was discovered by the
Frenchman Albert Fert and the German Peter Grünberg and earned them
the 2007 Nobel Prize in Physics. Up to a year ago, GMR was the
basis for the operation of read heads in almost all modern computer
hard disks. Now, however, a new generation of read heads is about
to hit the market: they offer a better performance based on the
quantum effects of TMR, resulting in an order of magnitude more
sensitive than that of tiny magnetic fields."
The record achieved by the IOM-CNR led to the creation, by the
group developing laboratory instrumentation, of an experimental
apparatus that enables the synthesis of the nanostructure. This was
made possible thanks to funding provided under regional law 26/2005
in Friuli Venezia Giulia.
"A significant advance in the development of new
high-performance materials with submicroscopic or functionalised
properties; these so-called smart materials," explains Roberto
Gotter, Head of the Instrumentation Development Group at IOM-CNR,
"are obtained through a synergy between innovative experimental
devices, developed ad hoc and not
mass-produced, and large research infrastructures.
For example, the Elettra synchrotron makes it possible to view,
understand and control the synthesis process on an atomic scale in
a way that is closely interrelated with the performance of magnetic
tunnelling junctions. It is precisely through a strategic role such
as this that, thanks to regional funding, IOM-CNR and the SPINOX
project have been able to create a special experimental station for
the synthesis of spintronics materials.
The station is in turn connected to the synchrotron beamlines,
and by means of the high-performance X-rays generated by the
Elettra storage ring, offers the international scientific community
unparalleled synthesis and analysis capability".