Projects / Programmes
Magnetic resonance and dielectric spectroscopy of condensed matter: The breaking of translational symmetry and "smart" new materials.
January 1, 2004
- December 31, 2008
Code |
Science |
Field |
Subfield |
1.02.00 |
Natural sciences and mathematics |
Physics |
|
Code |
Science |
Field |
P260 |
Natural sciences and mathematics |
Condensed matter: electronic structure, electrical, magnetic and optical properties, supraconductors, magnetic resonance, relaxation, spectroscopy |
New aperiodic materials and new techniques, spintronic materials, quasicrystals, complex metalic alloys, incommensurate systems, structural phase transitions, magnetoelectric organic and anorganic relaxors, nanomagnets and organic magnets, electron and nuclear magnetic resonance techniques for the study of local structure of disordered systems.
Researchers (29)
Organisations (1)
no. |
Code |
Research organisation |
City |
Registration number |
No. of publications |
1. |
0106 |
Jožef Stefan Institute |
Ljubljana |
5051606000 |
85,580 |
Abstract
The research program is focused on new aperiodic materials and the development of new techniques for the study of the local structure and dynamics of these systems. The purpose of these investigations is to discover the basic physical laws which govern the behaviour of these systems and provide a key to the understanding of their macroscopic properties and the discovery of new materials for various applications. The four basic directions of research are:
a) New materials for spintronics.
The basic concept of spintronics is the manipulation of spin currents in contrast to conventional electronics where the spin of the electron is ignored and only the electric charge and current are taken into account. Adding the spin degree of freedom provides for new effects and new functionalities (memory elements, quantum information processing, spin-transistors). Within the proposed program we want to study new semiconducting materials on the basis of TiO2 nanotubes with ferromagnetic electrodes on one side and new magnetoelectric materials which combine the properties of ferromagnets and ferroelectrics on the other side. We as well want to study the basic spin dynamics of these system on the local level.
b) New magnetoelectric organic and anorganic relaxors.
Relaxors and new magnetoelectric materials which simultaneously exhibit ferromagnetic and ferroelectric order open new possibilities for actuators, electromechanical converters, memory and electronic elements. We wish to determine the nature of the coupling between electric polarization and spontaneous magnetization in these systems and determine the basic physics of relaxors with special emphasis on new magnetoelectric relaxors.
c) Complex metalic alloys and quasicrystals.
Complex metalic alloys with giant unit cells in analogy with quasicrystals show some completely new properties which are never found in ordered systems: In spite of their metallic character their electric resistivity increases with decreasing temperature as in insulators. They also show extremelly low thermal conductivities and exceptional mechanical properties so that they are ideally suited for surface coatings in space and other high tech applications. We intend to determine the local structure and the phason and electron dynamics of these systems as well as their magnetic properties. This should be the basis for the synthesis of new such materials with prescribed properties.
d) Nanomagnets and organic magnets.
Nanomagnets on the basis of Mn12 allow for information storage on the molecular level. The limiting factor is macroscopic quantum tunneling of the manetization. We plan to investigate a new family of nanomagnets based on Mn4 which should have a significantly higher potential barier between the two magnetization directions leading to a decrease in quantum tunneling enabling data storage at higher, e.g. room temperatures. We also plan to study the origin of magnetism in purely organic magnets on the basis of C60.
The common feature of research under a), b), c) and d) is that the systems are disordered and their properties are basically determined by the local and not by the average structure. Therefore we plan to develop new magnetic resonance techniques specifically designed for the study of local structure and local dynamics: Frequency variable electron paramagnetic resonance, double and triple nuclear quadrupole resonance, 2D and 3D exchange NMR and relaxation time dispersion measurements. We plan to develop as well other new magnetic resonance techniques with industrial importance such as polarization enhanced nuclear quadrupole resonance for explosives and mine detection.
The proposed program represents a continuation of the research of our group which led to more than ten granted patents, more than 600 publications in international journals, among them 40 in Physical Review Letters and more than 12.000 citations in SCI.
Significance for science
Our research during 2004 - 2008 has contributed essentially to the understanding of basic physical principles of systems with broken translational symmetry with the focus on quasicrystals, relaxor ferroelectrics, elastomers, novel spintronic materials and spatially confined systems. In addition, our research has contributed to the education of young researchers and postgratuate students. Our results are important also for the development of new experimental measurement techniques based on the Nuclear Quadrupole Resonance, Nuclear Double Resonance, multipulse EPR spectroscopy and dynamical calorimetry. New technologically important materials were discovered as well. Members of the program group have published during 2004 - 2008 176 original scientific papers in international journals (including 1 Nature paper and 8 Phys. Rev. Letters), complemented by more than 50 invited lectures at the international scientific meetings. During 2004 - 2008, all published works of the members of the program group were cited 2900-times.
Significance for the country
The results of the research program have large impact on the development of international science and are hence important for the scientific promotion of Slovenia. We expose as the main achievements the application-ready discovery of direct conversion of electrical energy into mechanical energy by means of the giant electromechanical effect found in relaxors, the development and manufacturing of a prototype of supersensitive NQR detector for the landmine and explosive detection, the development of new super-batteries, the development of a new method for fast characterization of polyamide fibers and a new method for characterization of farmaceutical agents and the development of new spintronic nanomaterials. These concepts and products represent high technology of Slovenian origin.
Most important scientific results
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Most important socioeconomically and culturally relevant results
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