prof. Krzysztof Parlinski
Founder of Department of Materials Research by Computers
Institute of Nuclear Physics, Polish Academy of Sciences
tel: +48 12 63 78 209
The main effort has been directed on studies of crystal structures, phase transitions, and lattice dynamics of crystals using the ab initio approach. Systems of general intersts were studied: cubic ZrO2 ceramic-base material, hexagonal GaN used in light diodes, rhombohedral LiNbO3 applied in opto-electronic devices, tetragonal CuInSe2, AgGaSe2, AgGaTe2, CuInS2, CuFeS2, ZnSnP2 used also in solar cells, tetragonal SnO2, GeO2 - a crystal similar to stishovite, cubic TiC and ZrC - carbide crystals, cubic MgO, MgSiO3, Mg2SiO4, CaTiO3 - a geological important material, molecular crystals OC(NH2)2, hard material BN, other crystals ZnTe, FeBO3, β-FeSi2, CaCl2, HgSe, Al2O3, NiTi shape memory alloy, and intermetallics NiAl, TiAl.
For that crystals the phonon dispersion curves and phonon density of states has been calculated using the direct method. I have written a software, called Phonon which incorrporates the idea of the direct method, and which allows to calculate phonon dispersion relations and phonon density of states for any crystal, or even system represented by a supercell. The calculated phonon dispersion curves agree quite well (within 5% in frequency) with the coherent inelastic neutron scattering measurements, and Raman and infrared data.
Unstable crystalline structures show soft modes with imaginary frequencies. The soft modes are used to search for a stable structure. The analysis of the soft mode allows to find rather quickly the stable structure, and confines considerably the set of structures to be tested against stability.
- Domain structure in ferroelestics: computer simulation
- Microstructure of high Tc superconductors: computer simulation
- Incommensurate phases, Landau theory and phase transition. Topological defects as objects driving the commensurate- incommensurate phase transition, studied by computer simulation
- Dipolar glasses studied by computer simulation
- Quasicrystals studied by computer simulation
- Dynamicas of molecular crystals: analitycal theory
- Neutron scattering measurements on crystalline materials
- Group theory applied to the structural phase transitions
- Excitations and condensate in liquid He4
- Maria Sklodowska-Curie Award in Phyiscs of Polish Academy of Sciences, 2005