When I come to some conference, I usually know many passengers in the airplane, but we never meet in the city where we live. What a wonderful and mysterious matter the conference is! Each participant forgets about his own problems at his job, home, kindergarten, etc. Routine and bureaucracy cannot reach us while we are at conferences. At conferences, we decide to change our lifestyle. Nobody knows yet what we are going to discover, especially if we go to some conference, which is not in our every year schedule.
On 16–20 May 2016, I was at the XXII Polish–Czech Seminar on the Structural and Ferroelectric Phase Transitions. Hucisko is located in the deep Polish forest nearby the wonderful and picturesque Ogrodzieniec, Mirów, Bobolice and Pieskowa Skała medieval Castles and Ojców National Park. This abstractive atmosphere promised much science and diligence in organisation, which is the fingerprint as of Poland, as of Czech Republic. This is a biennial seminar, which is held either in Poland or in Czech Republic. The idea of Seminar (1979) belongs to Bożena Hilczer and Jan Fousek, the heads of the ferroelectrics groups in both countries at that time. Since then, it is regularly organised by the Institute of Molecular Physics, Polish Academy of Sciences, and the Institute of Physics, Czech Academy of Sciences.
The programme consisted of 52 oral presentations and 59 posters, together with numerous vivid conversations. The opening lecture was given by Professor Bartłomiej Andrzejewski, the Chairman and the head of the Department of Ferroelectrics of the Institute of Molecular Physics, Polish Academy of Sciences, who welcomed the participants and briefly summarised the history of seminar ().
Figure 1. Group photo of participants of the XXII Polish–Czech Seminar, Hucisko, Poland.
The invited lecture of Professor J. Hlinka from the Institute of Physics, Academy of Sciences of the Czech Republic, was given just after the opening ceremony and was devoted to the multiferroic materials (materials that simultaneously show ferromagnetism and ferroelectricity). The properties of structurally complex ferroelectric, antiferroelectric and multiferroic single crystal materials were reported, and the idea that chirality appears as a consequence of a continuous symmetry-breaking transition within the ferroelectric Bloch wall was discussed. There were many interesting talks about multiferroic materials. In particular, A. Bussmann-Holder from Max Planck Institute for Solid State Research, Germany, proposed a new strategy to achieve strong magnetic polar coupling by deriving the soft-mode frequency of EuTiO3 as a function of its lattice parameter. The corner-shared network of manganese and oxygen obtained by advanced synthesis was reported by B. Dabrowski from Northern Illinois University, USA. The Landau-type potential for multiferroic material BiFeO3 was suggested by P. Marton from the Institute of Physics, Czech Republic. The first-principles total-energy calculations of BiGaO3 in different crystal phases under pressure were reported by J. Kaczkowski from the Institute of Molecular Physics, Poland. Soft modes in several improper ferroelectrics and multiferroics were discussed by S. Kamba from the Institute of Physics, Czech Republic. The polarisation anisotropy of Raman scattering in BiFeO3 was reported by J. Pokorný from the Institute of Physics, Czech Republic. In particular, it was shown how this information can be employed to complement the information from the directional dispersion when analysing grain interfaces and ferroelastic domain walls in this material. A considerable increase in the dielectric permittivity in BiFeO3 doped with crystallites at high temperature was reported by K. Chybczyńska from the Institute of Molecular Physics, Poland.
Several reports were devoted to the specific properties of perovskites. V.V. Laguta from the Institute of Physics, Czech Republic, presented the study of the magnetic resonance spectra in EuTiO3. It was found that in the paramagnetic phase, magnetic resonance spectra are determined by magnetic dipole and exchange interactions between Eu2+ spins. Magnetic phase transitions in EuTiO3 and SrMnO3 and the low-energy atomic-like electronic structures were analysed in the report of R.J. Radwanski from the Institute of Physics, Poland. E. Langenberg from Universidad de Zaragoza, Spain, reported about X-ray diffraction measurements showing that the perovskite phase is stabilised over the non-ferroelectric hexagonal phase in epitaxial (Sr1-xBax)MnO3 thin films. Synthesis of zinc titanate on the textured substrate was reported by I. Bobowska from Lodz University of Technology, Poland. The local structure and dynamics across the antiferroelectric phase transition in PbZrO3 was reported by M. Paściak from the Institute of Physics, Czech Republic. The formation of a metallic state at the interface of the band insulators LaAlO3 and SrTiO3 was reported by T. Kopp from the University of Augsburg, Germany. This effect has become a prototype for the reconstruction of electronic states which exhibit a variety of phenomena such as negative compressibility, superconductivity and magnetism. Flexible ferroelectric hybrid fibres for soft body shape sensing were reported by T. Sebastian from the Laboratory for High Performance Ceramics, Switzerland. X-ray characterisation of co-doped tetragonal BaTiO3 ceramics was presented by R. Bujakiewicz-Koronska from the Institute of Physics, Poland.
A special section was devoted to reports of the students. There was an excellent opportunity for them to make short presentations about their research. M. Belyanchikov from Moscow Institute of Physics and Technology, Russia, reported about the single particle and collective states of water molecules in the matrix of beryl crystal lattice. A strongly anisotropic set of absorption resonances caused exclusively by the water subsystem was detected. R. Vilarinho from the University of Porto, Portugal, made presentation about the inclusion of magnetic non-active Jahn–Teller cations (Co3+, Cr3+, Fe3+) in the B-site of TbMnO3. The crucial effect of Fe3+ substitution was revealed and understood as a consequence of the competition between ferromagnetic and antiferromagnetic interactions. I. Rafalovskyi from the Institute of Physics, Czech Republic, discussed the crystalline solid solution Pb(Mg1/3Nb2/3)O3-PbTiO3 as a promising material for electromechanical sensor and actuator applications, and the corresponding lamellar heterostructures were investigated. Synthesis and characterisation of full homologue series of 4-pentyl-4-hydroxyazobenzene alkanotes was reported by I. Niezgoda from the University of Wroclaw, Poland. A correlation between the length of the ester chain and observed properties of our materials was discussed. The spin and lattice excitations of Ni3TeO6 ceramics and single crystals were reported by S. Skiadopoulou from the Institute of Physics, Czech Republic. The effect of hydrostatic pressure on proton conductivity in (NH4)4H2(SeO4)3 superionic crystal has been studied by Ł. Lindner from the Institute of Molecular Physics, Poland. All reports were excellent and concise, and the research was done on high scientific level.
There were several important talks about ferroelectricity in materials, which are not commonly used as ferroelectrics. A. Kholkin from the University of Aveiro, Portugal, reported about aromatic peptides that are capable of forming spontaneously some fascinating discrete and well-ordered structures at the nanoscale: nanotubes, nanospheres, nanofibrils and hydrogels. M. Rok from the University of Wroclaw, Poland, made presentation about organic materials exhibiting semiconducting and ferroelectric properties. It was noticed that hydrogen bonds should play a crucial role and that the molecular complex formation in the solid state substantially changes the symmetry of the molecule. In addition, changes in the environment of methyl groups affect their dynamics. A. Piecha-Bisiorek from the University of Wrocław, Poland, presented a new organic molecular-ionic salt material in which the elastic degrees of freedom play the essential role in the domain pattern resembling that of martensitic phase transitions. S. Yáñez-Vilar from the University of Santiago de Compostela, Spain, presented an experimental evidence of a twofold order–disorder structural phase transition sequence in perovskite-like [(CH3)2NH2][Mn(HCOO)3].
A number of excellent contributions were made about the domain walls in various materials. K. Gallo from the Royal Institute of Technology, Sweden, discussed the recent developments and current challenges to combine optical and ferroelectric functionalities on the LiNbO3 technology platform, taking advantage of nanotechnology and integrated optics. T. Sluka from the Swiss Federal Institute of Technology, Switzerland, made presentation about the charged domain walls in ferroelectrics possessing metallic conductivity, which can be created, displaced and erased inside a monolith of nominally insulating materials, and therefore are promising as elements for the envisaged reconfigurable nanoelectronics. P.S. Bednyakov from the Institute of Physics, Czech Republic, presented a simple room-temperature bulk method which creates regular patterns of electron-hole-compensated charged domain walls in crystals of prototypical proper ferroelectric BaTiO3. V. Stepkova from the Institute of Physics, Czech Republic, presented the Ginzburg–Landau–Devonshire modelling and demonstrated the possibility of interesting stable defect existence within the 180° Bloch-like domain wall in rhombohedral BaTiO3.
The liquid crystal (and generally the order–disorder) branch of reports was represented by several oral and poster presentations. R. Świetlik from the Institute of Molecular Physics, Poland, presented the charge ordering in low-dimensional organic conductors, that is, transition from uniform to non-uniform charge distribution of molecules in conducting chains or layers. Z. Galewski from the University of Wroclaw, Poland, presented investigation of mesogenic properties of new homologous series of 4ʹ-(4-ethoxyazobenzene) alkanoates. A. Bubnov from the Institute of Physics, Czech Republic, presented the new smart liquid crystalline polymethacrylates highly photosensitive in a broad spectral range, and also about the self-assembling photosensitive materials as functional dopants for organic photovoltaic cells. M. Glogarová from the Institute of Physics, Czech Republic, reported about the frustrated smectic liquid crystal phases in lactic acid derivatives and suggested how to escape from the frustration in the molecular packing by forming the phases with regular array of defects, composed of blocks of a homogeneous structure separated by twist grain boundaries. W. Kuczyński from the Institute of Molecular Physics, Poland, reported about the influence of the dye additive on the liquid crystals’ order parameter. V. Novotná from the Institute of Physics, Czech Republic, made presentation about the liquid crystalline derivatives with terphenyl molecular core and lactic acid unit as chiral moiety. The SmA*-SmC* phase sequence was found in the broad temperature interval. High values of the spontaneous polarisation and the tilt angle growing continuously on cooling up to 42° were observed. The liquid crystal mixtures demonstrating the blue phases were reported by K. Nowicka from the Institute of Molecular Physic, Poland. The temperature range, the number of various blue phases and the grain size of typical mosaic texture were analysed. Dielectric properties of new fluorinated liquid crystal compounds exhibiting ferro- and antiferroelectric phases were presented by P. Perkowski from Military University of Technology, Poland. Dynamics of collective modes in ferrorlectric liquid crystal gels was reported by S.A. Różański from Stanisław Staszic University of Applied Sciences in Piła, Poland, in particular, a decrease of the Goldstone mode dielectric strength in the hydrogen-bonded gel network was discussed. Optical investigations of isotropic-nematic and nematic-smectic A phase transitions in porous polyethylene terephthalate films filled with octyl-cyanobiphenyl were presented by D.V. Shmeliova from Moscow Technological University, Russia.
I would like to thank the whole team, Bartłomiej Andrzejewski, Katarzyna Chybczyńska, Andrzej Hilczer, Łukasz Lindner, Paweł Ławniczak, Ewa Markiewicz, Antoni Pawłowski, Katarzyna Pogorzelec-Glaser and Maria Zdanowska-Frączek for perfect organisation of the XXII Seminar and friendly and comfortable atmosphere, for well-organised social programme including a welcome reception, lunches, a conference dinner and a big choice of excursions. I wish the next XXIII Seminar success and new interesting presentations.