Nanomagnets Add New Dimension To Nanotechnology

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.*

Data storage

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.

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.

*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.