Diffraction studies and crystallography of magnetic and electronic materials
The neutron scattering in the field of magnetic and electronic materials presents extraordinary importance. To probe magnetic properties on atomic scale, neutron diffraction is an established technique and a unique method of choice, which allows perfect quantitative data interpretation. The magnetic moment of the neutron makes it a unique probe for magnetic properties in condensed matter on atomic scale. It gives a direct access to the spin and orbital distribution in the unit cell. In particular, magnetic structure determination is the foyer to the understanding of many fundamental phenomena in Condensed Matter research. Neutron and synchrotron techniques can be applied to investigate spin-state transitions, charge and orbital ordering, giant magneto-resistance, magnetoelectric materials as well as other emergent phenomena in frustrated materials such as spin ice, spin liquid behavior or other promising topological defects.
In our group we perform complementary diffraction studies in neutron and synchrotron sources, and apply structural and magnetic crystallography methods to investigate functional magnetic and electronic materials. So, e.g. in magnetically induced ferroelectrics, polarization can originate (but not exclusively) from exotic magnetic ground states (spiral, cycloidal, conical,..orders) that breaks inversion symmetry, thus generating an electric field and ferroelectricity. Moreover, normally these states can be easily modified or manipulated by external parameters (applied fields, pressure, temperature, strain, ..). A wide variety of mechanisms based on internal orders (structural, magnetic, electronic, ..) are now under intense investigation using diffraction techniques with synchrotron and neutron beams. The list of possible mechanisms and materials for multiferroic ground states is very far from complete. Our group is pioneer in applying new crystallographic methods of data analysis to tackle the original magnetic and structural orders that govern this interesting class of materials.