Feb 13 2008
It is well known that current technology tends to design
tools that are ever smaller and that nanotechnology, although it its
infancy, is a theme that is very much in fashion in our society. Who
has not heard of nanotubes, nanoparticles and nanomagnets, etc?
The PhD thesis by Ms Sonia Moralejo García,
defended at the Faculty of Science and Technology at the University of
the Basque Country (UPV/EHU), used various techniques to analyse the
manufacture of nanomagnets and magnetic devices of widespread
industrial application.
The PhD entitled, "Nanofabricación y propiedades
magnéticas de nanoimanes patronados de películas
delgadas "(The nanomanufacture and magnetic properties of nanomagnets
patterned with thin films) was led by Professor Fernando
Castaño Almendral and doctor Fernando Castaño
Sánchez, and obtained excellent cum laude. The researcher
has had the advantage of a number of study-stays in various
laboratories: the Max Planck Institute of Microstructure Physics in
Germany and the Cavendish Laboratory of the University of Cambridge in
the United Kingdom which contributed to completing her PhD thesis.
Sonia Moralejo García is a graduate in Chemical
Sciences from the University of the Basque Country and currently
continues to do her research at the Department of Chemical Sciences at
the university.
This work in the field of nanotechnology combines two
multidisciplinary experimental worlds, the technological and the
scientific. The technological is related to the manufacture of
nanomagnets and magnetic devices, for which a complete series of
techniques have been developed and/or made ready and which enable, from
start to finish, the obtaining of samples by conventional methods and
of wide industrial application. “Amongst other things, we
have created a system for growing a number of materials at the same
time, instead of just one at a time” said the researcher. In
this PhD, two materials have been mainly employed: Ni-Fe and Co-Fe
alloys.
Their magnetic behaviour has been studied, both as continuous
layers and as samples of smaller size (threads, circles, ellipses),
varying their shape and distances, given that they have different
behaviour patterns – knowing these is essential for the
different applications.
The magnetic behaviour of these materials was studied using
hysteresis. Such magnetic behaviour enables the storage of computer
hard discs in magnets: the magnetic field induces a magnetising of the
small magnet – codified in a binary manner as either 0 or 1
-; this codification remains in the absence of the magnetic field and
can be read subsequently, but it can also be inverted, applying a
magnetic field in the opposite sense.
As we have mentioned, the main applications of this type of
nanomagnets and magnetic devices are focused on the field of storage
and data treatment, hard discs, etc.
The manufacture of nanomagnets and magnetic devices at a small
scale has enabled having samples available and tackle problems of great
current interest in the field of nanomagnetism.
Although the beginning of this thesis was somewhat difficult,
given that what was involved was a new line of research for the
Department of Physical Chemistry at the UPV/EHU, forthwith they will
try to design and install new techniques and carry out trials on a
wider range of materials.