Download or read book Effects of Dielectric Relaxation on Director Dynamics in Uniaxial Nematic Liquid Crystals written by Mingxia Gu and published by . This book was released on 2009 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt: Director reorientation dynamics is essential to most of today's liquid crystal technologies. Advances in research have allowed one to reduce the response times from millisecond to microsecond and even to nanoseconds. For these small time scales, the description of the director dynamics requires a proper account of the dielectric dispersion effects. However, the first analysis of the role of dielectric dispersion in the director dynamics has been performed only very recently. Previous investigations were limited to dual frequency nematic liquid crystals, and considered only a single dielectric relaxation process. In this thesis, we lift these limitations and propose a model that accounts for multiple processes of dielectric relaxations in both parallel and perpendicular dielectric permittivities. The model yields a number of counterintuitive predictions such as the polar contribution to the dielectric coupling between the field and the nematic liquid crystal. The most important results are summarized below: First, we developed a general model to describe the director orientation dynamics of nematic liquid crystals under an applied electric field that accounts for multiple dielectric relaxations in both parallel and perpendicular dielectric permittivities. This model presents the contribution of dielectric relaxation as a "memory" effect; the director dynamics depends not only on the present electric and director fields, but also on their pre-histories. Second, we discovered an unusual contribution to the dielectric torque as a result of dielectric memory effect. This torque is linear in the present applied electric field and is thus sensitive to its polarity. The phenomenon is accompanied by a spectacular but counter-intuitive effect: the director relaxation during the "switch-off" stage can be accelerated if instead of an abrupt vertical back edge of the voltage pulse, we apply a pulse with a non-instantaneously vanishing back edge. Third, we demonstrate the director dynamics under different "shapes" of the front edge of the voltage pulses, taking into account the dielectric relaxation. Our model allows us to optimize the front edge of the pulse to improve switching efficiency. Finally, we studied the dynamics of electrically induced isotropic-nematic (I-N) phase transition by accounting for the finite rate of the polarization dynamics, which has previously been considered an instantaneous process in the classic theory. Consequently the electrically induced nematic order parameter does not interact directly with the applied electric field, but is mediated by the dynamics of polarization. We present a model based on the Langevin equation that describes the dynamics of two crucial parameters: the polar and non-polar order parameters during the electrically induced I-N phase transition.
Download or read book Dielectric Relaxation and Electrooptical Effects in Nematic Liquid Crystals written by Ye Yin and published by . This book was released on 2007 with total page 113 pages. Available in PDF, EPUB and Kindle. Book excerpt: Orientational dynamics of the nematic director in the applied electric field is a fundamental physical phenomenon that is at the heart of numerous modern technologies. Dielectric reorientation of the director is caused by a torque that depends on both the electric field and electric displacement. The finite rate of dielectric relaxation causes a time lag of the electric displacement as compared to the instantaneous value of the electric field. This effect which has been previously ignored is the subject of this review. We show that it causes profound effects when the characteristic time of the field changes is close to the dielectric relaxation time. Depending on the type of the nematic material, the characteristic relaxation times range from milliseconds (dual-frequency materials) to nanoseconds ("regular" materials such as pentylcyanobiphenyl). From the fundamental viewpoint, the problem is to determine the dielectric torque as a function of not only the present values of the electric field and director (as in the current theory), but of the previous values of these variables. As the modern industry demands nematic devices capable of switching within 1 ms or less, the issue of finite rate of dielectric relaxation becomes also of practical importance. We review recent experimental and theoretical works that link the phenomenon of dielectric relaxation in nematic liquid crystals to their fast electro-optical switching and also to the problem of dielectric heating. We discuss the theoretical model that allows one to relate director reorientation to the "history" of the electric field and the experimental verification of its validity. We analyze the effect of dielectric heating that is especially profound at the frequencies corresponding to dielectric relaxation. One of the important new results here is that the temperature raise depends on the state of director orientation. We also reported on a thermodielectric bistability in DFNs caused by the anisotropic nature of dielectric heating and director reorientation in an electric field. The bistability is a result of the positive feedback loop: director reorientation -> anisotropic dielectric heating -> dielectric anisotropy -> director reorientation. We demonstrate both experimentally and theoretically that two states with different temperature and director orientation, namely, a cold planar state and a hot homeotropic state coexist in a LC cell for a certain frequency and amplitude range of the applied voltage.
Download or read book Liquid Crystals With Nano And Microparticles In 2 Volumes written by Jan P F Lagerwall and published by World Scientific. This book was released on 2016-10-10 with total page 944 pages. Available in PDF, EPUB and Kindle. Book excerpt: 'The overall book content is excellently coordinated to form a synchronised story, interesting to a broad scientific audience … The book summarises the present knowledge in the field, introduces fundamental concepts to the beginners, describes key measuring methods and presents several different typical demonstrative systems, some of them exhibiting an extraordinary rich spectrum of structures and superstructures. I am sure that with time the book will become an attractor to a broad audience (physicists, chemists, material scientists, engineers, etc.), ranging from students, beginners in the field to experienced researchers. To summarise, this is the book that I have been missing on my bookshelf.'Liquid Crystals TodayWhile liquid crystals are today widely known for their successful application in flat panel displays (LCDs), academic liquid crystal research is more and more targeting situations where these anisotropic fluids are put to completely different use, in varying contexts. A particularly strong focus is on colloidal liquid crystals, where particles, bubbles or drops are dispersed in a liquid crystal phase. The liquid crystal can act as a host phase, with the inclusions constituting foreign guests that disturb the local order in interesting ways, often resulting in large-scale positional arrangement and/or uniform alignment of the guests. But it may also be formed by solid particles themselves, if these are of nanoscale dimensions and of disc- or rod-shape, and if they are suspended in an isotropic liquid host at sufficient concentration.This book aims to cover both the modern research tracks, gathering pioneering researchers of the different subfields to give a concise overview of the basis as well as the prospects of their respective specialties. The scope spans from curiosity-driven fundamental scientific research to applied sciences. Over the course of the next decade, the former is likely to generate new tracks of the latter type, considering the exploratory and productive phase of this young research field.
Download or read book Relaxation Phenomena written by Wolfgang Haase and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 732 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors describe the electric, magnetic and other relaxational processes in a wide spectrum of materials: liquid crystals, molecular magnets, polymers, high-Tc superconductors and glasses. The book summarizes the phenomenological fundamentals and the experimental methods used. A detailed description of molecular and collective dynamics in the broad range of liquid crystals is presented. Magnetic systems, high-Tc superconductors, polymers and glasses are an important subject of matter. It is shown that the researchers working on relaxation processes in different fields of materials sciences are dealing with the same physical fundamentals, but are sometimes using slightly different terms. The book is addressed to scientists, engineers, graduate and undergraduate students, experimentalists and theorists in physics, chemistry, materials sciences and electronic engineering. Many internationally well known experts contribute to it.
Download or read book The Langevin Equation written by William Coffey and published by World Scientific. This book was released on 2012 with total page 850 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume is the third edition of the first-ever elementary book on the Langevin equation method for the solution of problems involving the translational and rotational Brownian motion of particles and spins in a potential highlighting modern applications in physics, chemistry, electrical engineering, and so on. In order to improve the presentation, to accommodate all the new developments, and to appeal to the specialized interests of the various communities involved, the book has been extensively rewritten and a very large amount of new material has been added. This has been done in order to present a comprehensive overview of the subject emphasizing via a synergetic approach that seemingly unrelated physical problems involving random noise may be described using virtually identical mathematical methods in the spirit of the founders of the subject, viz., Einstein, Langevin, Smoluchowski, Kramers, The book has been written in such a way that all the material should be accessible both to an advanced researcher and a beginning graduate student. It draws together, in a coherent fashion, a variety of results which have hitherto been available only in the form of scattered research papers and review articles.
Download or read book Electro optical Effects of Liquid Crystals with Dielectric Dispersion written by Hugh Alan Wonderly and published by . This book was released on 2010 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: The dielectric dispersion in uniaxial nematic liquid crystals creates a "dielectric memory" effect whereby the polarization induced by the electric field decays exponentially with time rather than instantaneously, as in materials without dispersion. The induced polarization couples linearly with the electric field. This linear coupling allows one to accelerate the director relaxation towards the "off" state by a specially designed electric pulse of a proper polarity and duration We show theoretically and experimentally the possibility of electrically driving the director towards the off state, thereby decreasing the switching time. The effects, if any, of flexoelectric polarization on the response of the director are examined and found to be negligible.
Download or read book Advances in Liquid Crystal Research and Applications written by Lajos Bata and published by Elsevier. This book was released on 2013-10-22 with total page 704 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances in Liquid Crystal Research and Applications, Volume 1 is a collection of papers presented at the Third Liquid Crystal Conference of the Socialist Countries, held in Budapest on August 27-31, 1979. This volume is comprised of three parts. The first part deals with the phases and structures of liquid crystals through methods employing synthesis, X-ray studies, electron diffraction, and calorimetric determination. The second part discusses molecular dynamics and dynamical methods where mostly dielectric investigations into liquid crystal properties are emphasized. This part includes the developments in the study of molecular dynamics in liquid crystals. Other topics presented in this part are the acousto-optical and ultrasonic relaxation methods. The third part covers the continual properties of liquid crystals: their properties and behavior when exposed to different testing methods and variables. For example, a correlation between viscosity coefficients of starting components and those of their mixtures is attempted, resulting when MBBA and EBBA in different percentages are mixed, that none of their coefficients is found to obey any pronounced law. However, the viscosity coefficients given in the table may serve as reference data for further studies. Physicists; process engineers; and graduate students in physics, chemistry, and materials science fields; and university professors and lecturers related to studies in the field of liquid crystals will find this collection of papers highly informative and rewarding.
Download or read book Nonlinear Dielectric Phenomena in Complex Liquids written by Sylwester J. Rzoska and published by Springer Science & Business Media. This book was released on with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Langevin Equation The With Applications To Stochastic Problems In Physics Chemistry And Electrical Engineering 3rd Edition written by Yuri P Kalmykov and published by World Scientific. This book was released on 2012-07-31 with total page 850 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume is the third edition of the first-ever elementary book on the Langevin equation method for the solution of problems involving the translational and rotational Brownian motion of particles and spins in a potential highlighting modern applications in physics, chemistry, electrical engineering, and so on. In order to improve the presentation, to accommodate all the new developments, and to appeal to the specialized interests of the various communities involved, the book has been extensively rewritten and a very large amount of new material has been added. This has been done in order to present a comprehensive overview of the subject emphasizing via a synergetic approach that seemingly unrelated physical problems involving random noise may be described using virtually identical mathematical methods in the spirit of the founders of the subject, viz., Einstein, Langevin, Smoluchowski, Kramers, etc. The book has been written in such a way that all the material should be accessible both to an advanced researcher and a beginning graduate student. It draws together, in a coherent fashion, a variety of results which have hitherto been available only in the form of scattered research papers and review articles.
Download or read book Nematic Liquid Crystal Sessile Droplets In Electric And Magnetic Fields written by Zoltán Karaszi and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nematic Liquid Crystal Sessile Droplets in Electric and Magnetic Fields Abstract of Dissertation Zoltán Karaszi Materials Science Graduate Program, Kent State University Sessile droplets with uniform director structure could be used as tunable optical lenses where the focal length could be controlled by light polarization, viewing angle, and magnetic or electric fields. To achieve that, one must understand the liquid crystal director structure in various external fields. In this dissertation, I presented detailed experimental studies. I summarized the theoretical description of the director structure of uniaxial nematic liquid crystals, such as the formation and dynamics of Néel wall type metastable inversion walls, either in magnetic or electric fields or magnetic and electric fields combined. Sessile nematic droplets allow for studying the combined effect of anchoring at solid and gas interfaces. The combination of various alignments at the two surfaces and external fields results in various director distribution schemes, ranging from a defect-free, almost homogeneous state to configurations with point-, line- and wall defects. We designed a polarizing optical microscope made of non-magnetic materials that could be placed between an electromagnet's poles. The design allowed us to study the effect of various combinations of electric and magnetic fields on nematic liquid crystal sessile droplets. Additionally, a long-range microscope was used to observe the side view of the LC drop. We also built another experimental setup that enabled us to measure the focal length in response to electric fields while rotating the sample between crossed polarizers. (1) Our main experimental findings can be summarized as follows. We showed that under low magnetic fields applied along the base plane of a sessile droplet with homeotropic alignment, the director structure becomes distorted and gradually leads to a defect wall that moves toward the periphery. We explained the director field's magnetic field dependence and the defect walls' formation and motion. We have shown that at a strong enough lateral magnetic field or even at a small field that makes more than 3° with respect to the base plane, the director can be uniformly aligned along the field without the presence of the defect wall. [1] (2) Replacing the magnetic field, an AC electric field was applied along the base plane of a nematic sessile droplet with positive dielectric anisotropy; we also found a rotation of the director toward the electric field and the formation of an inversion wall perpendicular to the applied field. While at low frequencies, the direction of the wall was stationary, just as observed in magnetic fields, above the Maxwell-Wagner frequency, it turned toward the external electric field. In both cases, the defect wall was also swept toward the periphery of the drop, where it eventually disappeared. The defect wall's rotation at high frequencies resulted from the antiparallel orientation of the effective moment vector and the electric field due to the lower dielectric constant and higher electric conductivity of the defect wall than of the rest of the liquid crystal droplet. An exponential time dependence could describe the time dependence of the displacement of the electric field-induced defect wall without any fitting parameter. That, combined with the threshold for director deformation, enabled us to determine both the bend elastic constant and the rotational viscosity using much less substance than existing techniques. Uniform electric field-induced generation, rotation, and linear movement of defect walls is a unique phenomenon in soft matters.[2] (3) Multidimensional solitons and their electric field-induced movement have recently been reported in achiral and chiral nematic liquid crystals. In the presence of competing magnetic AC electric fields on a sessile droplet with positive dielectric anisotropy, we found that the inversion wall induced by a horizontal magnetic field suffers buckling at sufficiently high electric voltage applied vertically. We characterized the time and field dependence of the buckled walls' shape and motion and proposed a physical mechanism to account for the behavior. We note that, due to their spontaneous propagation, the inversion wall can also be considered as a one-dimensional soliton, i.e., a spatially localized shape preserving traveling wave packet such as observed first by J.S. Russell in 1834 in the form of a one-dimensional water wave traveling along a canal near Edinburgh. [3] (4) We also studied the behavior of nematic liquid crystal sessile droplets with negative dielectric anisotropy. We observed several new director configurations depending on the specific combination of the magnetic and electric fields. For example, at high enough voltages applied across the droplet, the radial symmetry breaks, and a spiraling deformation of the Maltese cross appears near the central defect line. This can be attributed to the twist deformation in the vicinity of the central defect line that replaces the more costly bend deformation. Applying a magnetic field perpendicular to the vertical electric field, a twisted inversion wall formed together with a vertical central defect line. When the electric field was applied parallel to the base plane of the droplet, a homeotropic central region formed along the electric field. When this field was applied together with a magnetic field in the same direction, the homeotropic central region became perpendicular to the applied field. [4,5] (5) We measured the focal length of nematic sessile droplets with positive dielectric anisotropy as a function of electric fields applied along the base plane of the lenses. It was observed that the focal length decreases during increasing fields as the effective refractive index, which is inversely proportional to the focal length, increases from "no" to "ne". The focal length of NLC droplets could also be tuned by varying the polarization direction of a linear polarizer placed in front of the lenses. At the same time, a constant AC electric field was applied along the base plane. [6] References: [1] P. Salamon, Z. Karaszi, V. Kenderesi, Buka, and A. Jákli, Liquid Crystal Spherical Caps in Magnetic Fields, Phys. Rev. Res. 2, 023261 (2020). [2] Z. Karaszi, P. Salamon, Á. Buka, and A. Jákli, Lens Shape Liquid Crystals in Electric Fields, J. Mol. Liq. 334, 116085 (2021). [3] Z. Karaszi, M. Máthé, P. Salamon, Á. Buka, and A. Jákli, Electric Field Induced Buckling of Inversion Walls in Lens-Shape Liquid Crystal Droplets, J. Mol. Liq. 365, 120177-1-7 (2022). [4] Z. Karaszi, M. Máthé, P. Salamon, Á. Buka, and A. Jákli, Lens-Shaped Nematic Liquid Crystal Droplets with Negative Dielectric Anisotropy in Electric and Magnetic Fields, Liq. Cryst. DOI: 10.1080/02678292.2022.2134594, published online (October 24, 2022). [5] Ágnes Buka, Péter Salamon, Marcell Máthé, Zoltán Karaszi, and Antal Jákli, Liquid Crystals, 2023, Nematic liquid crystals in lens shape geometry. https://doi.org/10.1080/02678292.2023.2168307 [6] Z. Karaszi, K. Perera, and A. Jákli, Tuning the Focal Length of Sessile Nematic Droplets by Electric Fields, under preparation, (2023).
Download or read book The Molecular Dynamics of Liquid Crystals written by G.R. Luckhurst and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 612 pages. Available in PDF, EPUB and Kindle. Book excerpt: Liquid-crystalline phases are now known to be formed by an ever growing range of quite diverse materials, these include those of low molecular weight as well as the novel liquid-crystalline polymers, such phases can also be induced by the addition of a solvent to amphiphilic systems leading to lyotropic liquid crystals. Irrespective of the structure of the constituent molecules these numerous liquid-cl)'Stailine phases are characterised by their long range orientational order. In addition certain phases exhibit elements of long range positional order. Our understanding, both experimental and theoretical, at the molecular level of the static behaviour of these fascinating and important materials is now well advanced. In contrast the influence of the long range order; both orientational and positional, on the molecular dynamics in liquid Cl)'Stais is less well understood. In an attempt to address this situation a NATO Advanced Study Institute devoted to liquid ctystal dynamics was held at n Ciocco, Barga, Italy in September 1989. This brought together experimentalists and theoreticians concerned with the various dynamical processes occurring in all liquid crystals. The skills of the participants was impressively wide ranging; they spanned the experimental techniques used in the study of molecular dynamics, the nature of the systems investigated and the theoretical models employed to understand the results. While much was learnt it was also recognised that much more needed to be done in order to advance our understanding of molecular dynamics in liquid Cl)'Stais.
Download or read book Thermotropic Liquid Crystals written by Ayyalusamy Ramamoorthy and published by Springer Science & Business Media. This book was released on 2007-05-06 with total page 331 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers developments in the field of thermotropic liquid crystals and their functional importance. It also presents advances related to different sub-areas pertinent to this interdisciplinary area of research. This text brings together research from synthetic scientists and spectroscopists and attempts to bridge the gaps between these areas. New physical techniques that are powerful in characterizing these materials are discussed.
Download or read book Handbook of Liquid Crystals 8 Volume Set written by John W. Goodby and published by John Wiley & Sons. This book was released on 2014-04-14 with total page 5240 pages. Available in PDF, EPUB and Kindle. Book excerpt: Much more than a slight revision, this second edition of the successful "Handbook of Liquid Crystals" is completely restructured and streamlined, with updated as well as completely new topics, 100% more content and a new team of editors and authors. As such, it fills the gap for a definitive, single source reference for all those working in the field of organized fluids and will set the standard for the next decade. The Handbook's new structure facilitates navigation and combines the presentation of the content by topic and by liquid-crystal type: A fundamentals volume sets the stage for an understanding of the liquid crystal state of matter, while individual volumes cover the main types and forms, with a final volume bringing together the diverse liquid crystal phases through their applications. This unrivaled, all-embracing coverage represents the undiluted knowledge on liquid crystals, making the Handbook a must-have wherever liquid crystals are investigated, produced or used, and in institutions where their science and technology is taught. Also available electronically on Wiley Online Library, www.wileyonlinelibrary.com/ref/holc Volume 1: Fundamentals of Liquid Crystals Volume 2: Physical Properties and Phase Behavior of Liquid Crystals Volume 3: Nematic and Chiral Nematic Liquid Crystals Volume 4: Smectic and Columnar Liquid Crystals Volume 5: Non-Conventional Liquid Crystals Volume 6: Nanostructured and Amphiphilic Liquid Crystals Volume 7: Supermolecular and Polymeric Liquid Crystals Volume 8: Applications of Liquid Crystals
Download or read book Optical Sensors and Microsystems written by S. Martellucci and published by Springer Science & Business Media. This book was released on 2007-05-08 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proceedings of the 22nd Course of the International School of Quantum Electronics, held 27 November-2 December 1997, in Erice, Italy. In recent years, fiber optical sensors and optical microsystems have assumed a significant role in sensing and measurement of many kinds. These optical techniques are utilised in a wide range of fields, including biomedicine, environmental sensing, mechanical and industrial measurement, and art preservation. This volume, an up-to-date survey of optical sensors and optical microsystems, aims at combining a tutorial foundation with analysis of current research in this area, and an extensive coverage of both technology and applications.
Download or read book Biaxial Nematic Liquid Crystals written by Geoffrey R. Luckhurst and published by John Wiley & Sons. This book was released on 2015-02-23 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the nematic liquid crystal phase, rod-shaped molecules move randomly but remain essentially parallel to one another. Biaxial nematics, which were first predicted in 1970 by Marvin Freiser, have their molecules differentially oriented along two axes. They have the potential to create displays with fast switching times and may have applications in thin-film displays and other liquid crystal technologies. This book is the first to be concerned solely with biaxial nematic liquid crystals, both lyotropic and thermotropic, formed by low molar mass as well as polymeric systems. It opens with a general introduction to the biaxial nematic phase and covers: • Order parameters and distribution functions • Molecular field theory • Theories for hard biaxial particles • Computer simulation of biaxial nematics • Alignment of the phase • Display applications • Characterisation and identification • Lyotropic, thermotropic and colloidal systems together with material design With a consistent, coherent and pedagogical approach, this book brings together theory, simulations and experimental studies; it includes contributions from some of the leading figures in the field. It is relevant to students and researchers as well as to industry professionals working in soft matter, liquid crystals, liquid crystal devices and their applications throughout materials science, chemistry, physics, mathematics and display engineering.
Download or read book Modeling of Soft Matter written by Maria-Carme T. Calderer and published by Springer Science & Business Media. This book was released on 2008-08-26 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt: This IMA Volume in Mathematics and its Applications MODELING OF SOFT MATTER contains papers presented at a very successful workshop with the same ti tle. The event, which was held on September 27-October 1, 2004, was an integral part of the 2004-2005 IMA Thematic Year on "Mathematics of Ma terials and Macromolecules: Multiple Scales, Disorder, and Singularities. " We would like to thank Maria-Carme T. Calderer (School of Mathematics, University of Minnesota) and Eugene M. Terentjev (Cavendish Laboratory, University of Cambridge) for their superb role as workshop organizers and editors of the proceedings. We take this opportunity to thank the National Science Foundation for its support of the IMA. Series Editors Douglas N. Arnold, Director of the IMA Arnd Scheel, Deputy Director of the IMA PREFACE The physics of soft matter in particular, focusing on such materials as complex fluids, liquid crystals, elastomers, soft ferroelectrics, foams, gels and particulate systems is an area of intense interest and contemporary study. Soft matter plays a role in a wide variety of important processes and application, as well as in living systems. For example, gel swelling is an essential part of many biological processes such as motility mecha nisms in bacteria and the transport and absorption of drugs. Ferroelectrics, liquid crystals, and elastomers are being used to design ever faster switch ing devices. Experiments of the last decade have provided a great deal of detailed information on structures and properties of soft matter.
Download or read book Nonlinear Dielectric Spectroscopy written by Ranko Richert and published by Springer. This book was released on 2018-06-18 with total page 377 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book introduces the ideas and concepts of nonlinear dielectric spectroscopy, outlines its history, and provides insight into the present state of the art of the experimental technology and understanding of nonlinear dielectric effects. Emphasis is on what can be learned from nonlinear experiments that could not be derived from the linear counterparts. The book explains that nonlinear dielectric spectroscopy can be used as a tool to measure structural recovery or physical aging, as well as connections between dynamics and thermodynamic variables such as enthalpy and entropy. Supercooled liquids in their viscous regime are ideal candidates for investigating nonlinear effects, because they are particularly sensitive to changes in temperature, and thus also to changes in the electric field. Other interesting materials covered are plastic crystals and complex liquids near criticality. The book also points out that, compared with other techniques such as mechanical shear experiments, the nonlinear regime of dielectric spectroscopy is special in the sense that the energies involved always remain small compared with thermal energies. To demonstrate this, nonlinear features of mechanical experiments are discussed. Theoretical approaches to nonlinear effects are particularly complicated because the tools available for the linear regime no longer apply. As a result, there is no single generally accepted theory to nonlinear dielectric responses of real liquids. Various approaches to nonlinear dielectric features have been reported, and the different aspects are communicated in several chapters. The book communicates recent progress most effectively through individual contributions from specialists in their respective fields. Chapter 'Third and Fifth Harmonic Responses in Viscous Liquids' is available open access under a Creative Commons Attribution 4.0 International License via link.springer.com.
