The project aims at development of novel magnetic nanostructures showing the effect of a negative index of refraction (e<0 and µ<0), named as left handed materials, using low cost and environmentally friendly processes such as sputtering and chemical-self assembly. The main objective of this proposal is through a trial and error process, but also based on existing theoretical models, to explore the possibility to demonstrate the reverse Snell's law behaviour of these nanostructures. In addition to structural and magnetic properties studies the frequency dependence of e and in the GHz regime will be studied using a Network analyser (S-parameter measurements). The positive results of such a coordinated effort by two specialized teams, will be the basis for a more extended effort in EC with positive impact in a number of industries, especially in telecommunications.
The aim of the project is to develop new nanomagnetic materials suitable for demonstration of left handed properties namely, negative dielectric constant and negative magnetic permeability in the frequency range of 1-40 GHz. This goal sets the following specific objectives: a) form magnetic nanorod structures which look similar to the metallic structures already studied b) prepare metallic-magnetic particles embedded in a dielectric matrix with e<0 in a narrow frequency range c) form magnetic needle-shaped nanoparticles and disperse them in a dielectric matrix (e<0), and d) characterize them with respect to microstructural, magnetic and more important the frequency dependence of their effective dielectric constant and magnetic permeability , with the projection that at some frequency close to plasma frequency- range the values will be negative.
DESCRIPTION OF WORK
The work is separated into two main parts:
A) The mastering of the growth of nanomagnetic structures using physical vapour techniques, electroplating and chemical synthesis. The partners will define standard operating procedures by the beginning of the work. Specifications will be based on existing models, but also on the continuous theoretical progress going on in one's partner lab. These structures will be first characterised using standard XRD, SEM and TEM techniques and for their magnetic properties using a SQUID, a-c and VSM magnetometers;
B) For the crucial properties of the left handed materials, frequency dependence of permitivity and permeability, a modified tester for films measurements based on an HP-Network analyser will be employed. The temperature range will be varied from L.N to R.T. The results will be analysed with the help of existing software (S-parameter measurements) based on previous experience of the partner's labs, namely in devices based in magnetic nanowires and high temperature superconductors. All the proposed structures will be evaluated at different stoichiometries in the range below the percolation threshold but above the ferromagnetic threshold.