|Dielectric and IR spectroscopy||THz science and technology||Light and neutron scattering||
|Solid-state materials science||
Main activities of Department of Dielectrics cover experimental and theoretical investigations of high-permittivity insulators like liquid crystals, ferroelectrics, multiferroics, piezoelectrics, semiconductor nanostructures, and low-loss materials.
- Dielectric and IR spectroscopy
- THz science and technology
- Light and neutron scattering
- Theory and simulations
- Solid-state materials science
- Liquid crystals
The most significant fresh scientific results of our deparment are listed in the section Highlights.
Václav Janovec has passed away
One of the founders of the Department of Dielectrics, outstanding scientist, editor and teacher, enthusiastic promoter of symmetry approaches to ferroic phase transitions and domain boundaries, Prof. Václav Janovec, our beloved friend and colleague Vašek, has passed away on February 16, 2022, at the age of his almost complete 92.
Alexey Bubnov took the 2nd place in the FZU Photo Competition 2021
Alexey Bubnov defended his second place in the FZU Photo Competition 2021. Moreover, he obtained 4th and 10-11th places for his images of liquid crystal textures in polarised light microscope. Futhermore, Maryam Mansoori Kermani and Fedir Borodavka got 5-9th and 10-11th place, respectively.
Picosecond nonlinear optoelectronics in graphene
Petr Kužel and Vaisakh Chelod Paingad in collaboration with colleagues from the Charles University described nonlinear behavior of charge carriers during early times after pulsed optical excitation in epitaxially grown graphene layers. The time evolution of the system is determined by nonlinear electronic response of graphene, which opens the possibility of the increase of the speed of optoelectronic elements [Adv. Funct. Mater. 31, 2105763 (2021)].
Second place for Pavel Baláž in Photogenic Science Competition 2021
A photo of (un)usual window cleaning during home office brought the second place to Pavel Baláž in the category of ‘Scientists and Home Office’. The competition is organized by the Czech Academy of Sciences and by the association Science is Alive! (Věda žije! in Czech) and its aim is to promote science by intriguing photos taken by scientists.
Karel Tesař took the 2nd place in the Falling Walls Lab competition
Karel Tesař was awarded for 'breaking the wall' with his project 'Post sternotomy chest pain' at Falling Walls Lab Wroclaw on 29 September 2021.
Subterahertz collective dynamics of polar vortices
An artist take on the 'whirling' vibrational mode revealed in the polar vortex structure of PbTiO3/SrTiO3 superlattices [Nature 592, 376 (2021)] to highlight the front cover of the April issue of Nature.
Multidomain ordered metal–ferroelectric superlattices
By combination of advanced experimental techniques and phase-field simulations, we found that electric dipoles in superlattices, composed of layers of a ferroelectric material separated by thin metallic spacers, form an unusual pattern of nanoscale domains that order in three dimensions. These ferroelectric multidomain ordered superlattices exhibit an outstanding dielectric response and their engineered modulated structural and electronic properties can be controlled using electric field [Nat. Mater. 20, 495 (2021)].
Ferroelectric and antiferroelectric phases in liquid crystalline compounds with terphenyl in the molecular coere
We designed a new type of antiferroelectric liquid crystalline structure with terphenyl in the molecular core and two lactate units attached to the chiral chain [J. Mol. Liq. 336, 116267 (2021)].
Ferroelectric phase transition in water molecules localized in mineral cordierite
We discovered that hydrogen bonds are eliminated and the Coulombic interactions dominate in water molecules localized in nano-channels of mineral cordierite. Their dipole moment is perpendicular to the channel axis c and our dielectric spectroscopy study have revealed their ordering at ~3 K. The critical relaxation tending to this ordering is polarized along the a-axis direction and lies in the radiofrequency range. Spontaneous polarization measurements yield the saturated value of ~3 nC/cm2 at 0.3 K [Nat. Commun. 11, 3927 (2020)].