Editorial

This special issue presents selected contributions from the XXIII Czech–Polish Seminar on Structural and Ferroelectric Phase Transitions held on May 21–25, 2018 in Kouty, Czech Republic. The Seminar was attended by 110 participants, mostly from the Czech Republic (45 participants) and Poland (37), but there were also participants from Germany, the USA, Austria, the Russian Federation, Switzerland, Hungary, Croatia, France, Ireland, Japan, Israel and Luxembourg. The schedule included 54 oral presentations of different lengths and 59 poster presentations. Most participants reported their recent published and unpublished scientific work, some lectures were of tutorial character, and several contributions highlighting challenges and open problems helped to fuel the usual vivid discussions, often extended to late evening hours (Figure 1).

Figure 1. Participants of the Czech–Polish Seminar 2018 (photo by Jan Pokorný).

The program covered various subjects related to structural and ferroelectric phase transitions. Invited presentations were given by P. Paruch, P. Alpay, P. Márton, Y. Ivry, P. Bednyakov, E. Buixaderas, P. Ławniczak, S. Suwa, I. Kézsmárki, M. Guennou, S. Nakhmanson, B. Andrzejewski, I. Jankowska-Sumara, and K. Roleder. Impression about the scope of the discussed subjects can be grasped from recent publications of the participants including contributions to this special issue. Specific materials involved in the presented studies comprised classical ferroelectrics like lead germanate [1] and barium titanate [2] as well as more peculiar materials such as crystals from hexaferrite, corundum and lacunar spinel families, showing simultaneous polar and magnetic ordering [3-8]. Traditional subjects of interest were devoted to relaxor materials from the family of complex perovskites and the family of uniaxial tetragonal tungsten bronzes [9-13], and a whole session was devoted to polar effects, chirality, excitations, phase transitions and photosensitive properties of liquid crystals [14-18]. Participants thoroughly discussed material science issues related to preparation of materials [19-22], but also dielectric, piezoelectric and caloric effects from the point of view of prospective applications [23-27]. General material design strategies for antiferroelectric, antidistortive and chiroaxial materials [28-31] and mesoscale modeling [32-34] were discussed as well. Quite a few subjects were related to theoretical and experimental investigations of domain walls, in particular in connection to their pinning [35,36], trapping of electrons by them [37] and their observation by means of nonlinear optic microscopy [38], atomic probe imaging [39], Raman spectroscopy [40] and dynamical mechanical analysis [41]. Attention was attracted by several new technical developments, such as optical tomography method allowing to image domain structures in materials like LiNbO₃ [42] or progress in inelastic electron scattering techniques allowing to probe surface phonon modes in dielectric thin films [43].

It can be concluded that 40 years after its foundation, the Seminar remains a traditional, successful and motivating event, at the same time becoming a meeting of an international character. It is my pleasure to thank my colleagues from the Institute of Physics, Czech Academy of Sciences and the Union of Czech Mathematicians and Physicists, in particular to M. Janovská, V. Novotná, A. Bubnov, and J. Pokorný for their effort in organization of this event, as well as to my colleagues M. Paściak and S. Kamba from the Institute of Physics, Czech Academy of Sciences, B. Andrzejewski from the Institute of Molecular Physics, Polish Academy of Sciences and K. Roleder from the University of Silesia in Katowice for their essential contribution to assembling and editing this special issue.

I would also like to thank the editor-in-chief of Phase Transitions Professor Jens Kreisel and the T&F team whose efforts made this special issue possible, beginning with the editorial decisions and throughout the whole production process of this volume.

Prague, August 21, 2018