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Organic Ferroelectric Materials and Applications

Organic Ferroelectric Materials and Applications Book
Author : Kamal Asadi
Publisher : Woodhead Publishing
Release : 2021-10-15
ISBN : 9780128215517
Language : En, Es, Fr & De

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Book Description :

Organic Ferroelectric Materials and Applications aims to bring an up-to date account of the field with discussion of recent findings. This book presents an interdisciplinary resource for scientists from both academia and industry on the science and applications of molecular organic piezo- and ferroelectric materials. The book addresses the fundamental science of ferroelectric polymers, molecular crystals, supramolecular networks, and other key and emerging organic materials systems. It touches on important processing and characterization methods and provides an overview of current and emerging applications of organic piezoelectrics and ferroelectrics for electronics, sensors, energy harvesting, and biomedical technologies. Organic Ferroelectric Materials and Applications will be of special interest to those in academia or industry working in materials science, engineering, chemistry, and physics. Provides an overview of key physical properties of the emerging piezoelectric and ferroelectric molecular and supramolecular systems Discusses best practices of processing, patterning, and characterization methods and techniques Addresses current and emerging applications for electronics, materials development, sensors, energy harvesting, and biomedical technologies

Ferroelectric Materials and Their Applications

Ferroelectric Materials and Their Applications Book
Author : Y. Xu
Publisher : Elsevier
Release : 2013-10-22
ISBN : 1483290956
Language : En, Es, Fr & De

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Book Description :

This book presents the basic physical properties, structure, fabrication methods and applications of ferroelectric materials. These are widely used in various devices, such as piezoelectric/electrostrictive transducers and actuators, pyroelectric infrared detectors, optical integrated circuits, optical data storage, display devices, etc. The ferroelectric materials described in this book include a relatively complete list of practical and promising ferroelectric single crystals, bulk ceramics and thin films. Included are perovskite-type, lithium niobate, tungsten-bronze-type, water-soluable crystals and other inorganic materials, as well as organic ferroelectrics (polymers, liquid crystals, and composites). Basic concepts, principles and methods for the physical property characteristics of ferroelectric materials are introduced in the first two chapters for those readers new to the subject of ferroelectricity. Not only professional researchers and engineers but also students and other readers who have limited physical knowledge and an interest in ferroelectrics, will welcome this book.

Ferroelectric Materials for Energy Applications

Ferroelectric Materials for Energy Applications Book
Author : Haitao Huang,James F. Scott
Publisher : John Wiley & Sons
Release : 2019-01-04
ISBN : 3527342710
Language : En, Es, Fr & De

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Book Description :

Provides a comprehensive overview of the emerging applications of ferroelectric materials in energy harvesting and storage Conventional ferroelectric materials are normally used in sensors and actuators, memory devices, and field effect transistors, etc. Recent progress in this area showed that ferroelectric materials can harvest energy from multiple sources including mechanical energy, thermal fluctuations, and light. This book gives a complete summary of the novel energy-related applications of ferroelectric materials?and reviews both the recent advances as well as the future perspectives in this field. Beginning with the fundamentals of ferroelectric materials, Ferroelectric Materials for Energy Applications offers in-depth chapter coverage of: piezoelectric energy generation; ferroelectric photovoltaics; organic-inorganic hybrid perovskites for solar energy conversion; ferroelectric ceramics and thin films in electric energy storage; ferroelectric polymer composites in electric energy storage; pyroelectric energy harvesting; ferroelectrics in electrocaloric cooling; ferroelectric in photocatalysis; and first-principles calculations on ferroelectrics for energy applications. -Covers a highly application-oriented subject with great potential for energy conversion and storage applications. -Focused toward a large, interdisciplinary group consisting of material scientists, solid state physicists, engineering scientists, and industrial researchers -Edited by the "father of integrated ferroelectrics" Ferroelectric Materials for Energy Applications is an excellent book for researchers working on ferroelectric materials and energy materials, as well as engineers looking to broaden their view of the field.

Piezoelectricity

Piezoelectricity Book
Author : Savvas G. Vassiliadis,Dimitroula Matsouka
Publisher : BoD – Books on Demand
Release : 2018-08-29
ISBN : 1789236460
Language : En, Es, Fr & De

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Book Description :

Scientifically defined in 1880 by the Curie brothers, piezoelectricity - from the Greek piezein, meaning to press (squeeze), and ilektron, meaning amber, a material with electrostatic properties - is a phenomenon with many applications. The related piezoelectric materials have been undergoing a long-lasting evolution over the years until today. The field of organic and inorganic piezoelectric materials is continuously expanding in terms of new substances used, new structures, and new applications. The seven chapters of this book present modern aspects and technological advances in the field of piezoelectric materials and applications. To present a balanced view of the field, some chapters focus on new piezoelectric materials and structures, while others examine interesting applications of piezoelectric sensors, energy harvesters, and actuators.

Ferroelectric Materials for Energy Applications

Ferroelectric Materials for Energy Applications Book
Author : Haitao Huang,James F. Scott
Publisher : John Wiley & Sons
Release : 2018-08-31
ISBN : 3527807497
Language : En, Es, Fr & De

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Book Description :

Provides a comprehensive overview of the emerging applications of ferroelectric materials in energy harvesting and storage Conventional ferroelectric materials are normally used in sensors and actuators, memory devices, and field effect transistors, etc. Recent progress in this area showed that ferroelectric materials can harvest energy from multiple sources including mechanical energy, thermal fluctuations, and light. This book gives a complete summary of the novel energy-related applications of ferroelectric materials?and reviews both the recent advances as well as the future perspectives in this field. Beginning with the fundamentals of ferroelectric materials, Ferroelectric Materials for Energy Applications offers in-depth chapter coverage of: piezoelectric energy generation; ferroelectric photovoltaics; organic-inorganic hybrid perovskites for solar energy conversion; ferroelectric ceramics and thin films in electric energy storage; ferroelectric polymer composites in electric energy storage; pyroelectric energy harvesting; ferroelectrics in electrocaloric cooling; ferroelectric in photocatalysis; and first-principles calculations on ferroelectrics for energy applications. -Covers a highly application-oriented subject with great potential for energy conversion and storage applications. -Focused toward a large, interdisciplinary group consisting of material scientists, solid state physicists, engineering scientists, and industrial researchers -Edited by the "father of integrated ferroelectrics" Ferroelectric Materials for Energy Applications is an excellent book for researchers working on ferroelectric materials and energy materials, as well as engineers looking to broaden their view of the field.

Molecular Modeling and Multiscaling Issues for Electronic Material Applications

Molecular Modeling and Multiscaling Issues for Electronic Material Applications Book
Author : Artur Wymyslowski,Nancy Iwamoto,Matthew Yuen,Haibo Fan
Publisher : Springer
Release : 2014-11-20
ISBN : 3319128620
Language : En, Es, Fr & De

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Book Description :

This book offers readers a snapshot of the progression of molecular modeling in the electronics industry and how molecular modeling is currently being used to understand materials to solve relevant issues in this field. The reader is introduced to the evolving role of molecular modeling, especially seen from the perspective of the IEEE community and modeling in electronics. This book also covers the aspects of molecular modeling needed to understand the relationship between structures and mechanical performance of materials. The authors also discuss the transitional topic of multiscale modeling and recent developments on the atomistic scale and current attempts to reach the submicron scale, as well as the role that quantum mechanics can play in performance prediction.

Applications of Metal Organic Frameworks and Their Derived Materials

Applications of Metal Organic Frameworks and Their Derived Materials Book
Author : Inamuddin,Rajender Boddula,Mohd Imran Ahamed,Abdullah M. Asiri
Publisher : John Wiley & Sons
Release : 2020-04-23
ISBN : 1119651166
Language : En, Es, Fr & De

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Book Description :

Metal–organic frameworks (MOFs) are porous crystalline polymers constructed by metal sites and organic building blocks. Since the discovery of MOFs in the 1990s, they have received tremendous research attention for various applications due to their high surface area, controllable morphology, tunable chemical properties, and multifunctionalities, including MOFs as precursors and self-sacrificing templates for synthesizing metal oxides, heteroatom-doped carbons, metal-atoms encapsulated carbons, and others. Thus, awareness and knowledge about MOFs and their derived nanomaterials with conceptual understanding are essential for the advanced material community. This breakthrough new volume aims to explore down-to-earth applications in fields such as biomedical, environmental, energy, and electronics. This book provides an overview of the structural and fundamental properties, synthesis strategies, and versatile applications of MOFs and their derived nanomaterials. It gives an updated and comprehensive account of the research in the field of MOFs and their derived nanomaterials. Whether as a reference for industry professionals and nanotechnologists or for use in the classroom for graduate and postgraduate students, faculty members, and research and development specialists working in the area of inorganic chemistry, materials science, and chemical engineering, this is a must-have for any library.

The Electrical Engineering Handbook Second Edition

The Electrical Engineering Handbook Second Edition Book
Author : Richard C. Dorf
Publisher : CRC Press
Release : 1997-09-26
ISBN : 9781420049763
Language : En, Es, Fr & De

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Book Description :

In 1993, the first edition of The Electrical Engineering Handbook set a new standard for breadth and depth of coverage in an engineering reference work. Now, this classic has been substantially revised and updated to include the latest information on all the important topics in electrical engineering today. Every electrical engineer should have an opportunity to expand his expertise with this definitive guide. In a single volume, this handbook provides a complete reference to answer the questions encountered by practicing engineers in industry, government, or academia. This well-organized book is divided into 12 major sections that encompass the entire field of electrical engineering, including circuits, signal processing, electronics, electromagnetics, electrical effects and devices, and energy, and the emerging trends in the fields of communications, digital devices, computer engineering, systems, and biomedical engineering. A compendium of physical, chemical, material, and mathematical data completes this comprehensive resource. Every major topic is thoroughly covered and every important concept is defined, described, and illustrated. Conceptually challenging but carefully explained articles are equally valuable to the practicing engineer, researchers, and students. A distinguished advisory board and contributors including many of the leading authors, professors, and researchers in the field today assist noted author and professor Richard Dorf in offering complete coverage of this rapidly expanding field. No other single volume available today offers this combination of broad coverage and depth of exploration of the topics. The Electrical Engineering Handbook will be an invaluable resource for electrical engineers for years to come.

Electrical Memory Materials and Devices

Electrical Memory Materials and Devices Book
Author : Wen-Chang Chen
Publisher : Royal Society of Chemistry
Release : 2015-10-16
ISBN : 1782622500
Language : En, Es, Fr & De

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Book Description :

Information technology is essential to our daily life, and the limitations of silicone based memory systems mean a growing amount of research is focussed on finding an inexpensive alternative to meet our needs and allow the continued development of the industry. Inorganic silicone based technology is increasingly costly and complex and is physically limited by the problems of scaling down. Organic electrical memory devices are comparatively low cost, offer flexibility in terms of chemical structure, are compatible with flexible substrates and allow easy processing. For these reasons polymeric memory nanoscale materials are considered by many to be a potential substitute for conventional semiconductor memory systems. This edited book focusses solely on organic memory devices, providing a full background and overview of the area before bringing the reader up to date with the current and ongoing research in this area. The broad appeal of this book will be applicable to a wide range of researchers and those working in industry, in particular those working in materials, electrical and chemical engineering.

Electrically Active Materials for Medical Devices

Electrically Active Materials for Medical Devices Book
Author : Syed A M Tofail,Joanna Bauer
Publisher : World Scientific
Release : 2016-08-04
ISBN : 178326988X
Language : En, Es, Fr & De

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Book Description :

Stress induced electrical charges, action potential and electret behavior of bone, muscles, skin and nerve cells have been known for some time. Electrically Active Materials for Medical Devices builds on this knowledge and encourages readers to understand and exploit electrical activity in biomaterials from native, derived, or completely synthetic origin, or a combination thereof. It presents data and insights from both historic and contemporary research that spans over six decades with a view to generate convergence of interdisciplinary knowledge and skills. Divided into four parts, this book first introduces the reader to a general overview of electrically active materials in biology and biomedical science and describes important concepts and pioneering discoveries. The second part discusses common types of materials that are known to generate electrical activity and lays the foundation for these materials for use in medical devices. The third part gives examples of where electrically active materials have been examined for device application. The final part looks for upcoming and emerging concepts, tools and methodologies that are expected to shape the future profile of this field of converging science. Written by specialists in their respective fields, it has been specifically targeted at a readership of professionals, graduate students and researchers in the fields of biomedical engineering, physics, chemistry biology and clinical medicine.

Ferroelectric Gate Field Effect Transistor Memories

Ferroelectric Gate Field Effect Transistor Memories Book
Author : Byung-Eun Park,Hiroshi Ishiwara,Masanori Okuyama,Shigeki Sakai,Sung-Min Yoon
Publisher : Springer Nature
Release : 2020-03-23
ISBN : 9811512124
Language : En, Es, Fr & De

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Book Description :

This book provides comprehensive coverage of the materials characteristics, process technologies, and device operations for memory field-effect transistors employing inorganic or organic ferroelectric thin films. This transistor-type ferroelectric memory has interesting fundamental device physics and potentially large industrial impact. Among various applications of ferroelectric thin films, the development of nonvolatile ferroelectric random access memory (FeRAM) has been most actively progressed since the late 1980s and reached modest mass production for specific application since 1995. There are two types of memory cells in ferroelectric nonvolatile memories. One is the capacitor-type FeRAM and the other is the field-effect transistor (FET)-type FeRAM. Although the FET-type FeRAM claims the ultimate scalability and nondestructive readout characteristics, the capacitor-type FeRAMs have been the main interest for the major semiconductor memory companies, because the ferroelectric FET has fatal handicaps of cross-talk for random accessibility and short retention time. This book aims to provide the readers with development history, technical issues, fabrication methodologies, and promising applications of FET-type ferroelectric memory devices, presenting a comprehensive review of past, present, and future technologies. The topics discussed will lead to further advances in large-area electronics implemented on glass, plastic or paper substrates as well as in conventional Si electronics. The book is composed of chapters written by leading researchers in ferroelectric materials and related device technologies, including oxide and organic ferroelectric thin films.

Ferroelectrics and Their Applications

Ferroelectrics and Their Applications Book
Author : Husein Irzaman,Renan Prasta Jenie
Publisher : BoD – Books on Demand
Release : 2018-10-03
ISBN : 1789840139
Language : En, Es, Fr & De

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Book Description :

Ferroelectricity is a symptom of inevitable electrical polarization changes in materials without external electric field interference. Ferroelectricity is a phenomenon exhibited by crystals with a spontaneous polarization and hysteresis effects associated with dielectric changes when an electric field is given. Our fascination with ferroelectricity is in recognition of a beautiful article by Itskovsky, in which he explains the kinetics of a ferroelectric phase transition in a thin ferroelectric layer (film). We have been researching ferroelectric materials since 2001. There are several materials known for their ferroelectric properties. Barium titanate and barium strontium titanate are the most well known. Several others include tantalum oxide, lead zirconium titanate, gallium nitride, lithium tantalate, aluminium, copper oxide, and lithium niobate. There is still a blue ocean of ferroelectric applications yet to be expounded. It is and hopefully always will be a bright future.

Ferroelectrics

Ferroelectrics Book
Author : Indrani Coondoo
Publisher : BoD – Books on Demand
Release : 2010-12-14
ISBN : 9533074396
Language : En, Es, Fr & De

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Book Description :

Ferroelectric materials exhibit a wide spectrum of functional properties, including switchable polarization, piezoelectricity, high non-linear optical activity, pyroelectricity, and non-linear dielectric behaviour. These properties are crucial for application in electronic devices such as sensors, microactuators, infrared detectors, microwave phase filters and, non-volatile memories. This unique combination of properties of ferroelectric materials has attracted researchers and engineers for a long time. This book reviews a wide range of diverse topics related to the phenomenon of ferroelectricity (in the bulk as well as thin film form) and provides a forum for scientists, engineers, and students working in this field. The present book containing 24 chapters is a result of contributions of experts from international scientific community working in different aspects of ferroelectricity related to experimental and theoretical work aimed at the understanding of ferroelectricity and their utilization in devices. It provides an up-to-date insightful coverage to the recent advances in the synthesis, characterization, functional properties and potential device applications in specialized areas.

Switching Kinetics and Charge Transport in Organic Ferroelectrics

Switching Kinetics and Charge Transport in Organic Ferroelectrics Book
Author : Tim Cornelissen
Publisher : Linköping University Electronic Press
Release : 2020-08-26
ISBN : 9179298281
Language : En, Es, Fr & De

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Book Description :

The continued digitalization of our society means that more and more things are getting connected electronically. Since currently used inorganic electronics are not well suited for these new applications because of costs and environmental issues, organic electronics can play an important role here. These essentially plastic materials are cheap to produce and relatively easy to recycle. Unfortunately, their poor performance has so far hindered widespread application beyond displays. One key component of any electronic device is the memory. For organic electronics several technologies are being investigated that could serve as memories. One of these are the ferroelectrics, materials that have a spontaneous electrical polarization that can be reversed with an electric field. This bistable polarization which shows hysteresis makes these materials excellent candidates for use as memories. This thesis focuses on a specific type of organic ferroelectric, the supramolecular discotics. These materials consist of disk?like molecules that form columns in which all dipolar groups are aligned, giving a macroscopic ferroelectric polarization. Of particular interest are the benzenetricarboxamides (BTA), which are used as a model system for the whole class of discotic ferroelectrics. BTA uses a core?shell architecture which allows for easy modification of the molecular structure and thereby the ferroelectric properties. To gain a deeper understanding of the switching processes in this organic ferroelectric BTA, both microscopic and analytical modeling are used. This is supported by experimental data obtained through electrical characterization. The microscopic model reduces the material to a collection of dipoles and uses electrostatics to calculate the probability that these dipoles flip. These flipping rates are the input for a kinetic Monte Carlo simulation (kMC), which simulates the behavior of the dipoles over time. With this model we simulated three different switching processes on experimental time and length scales: hysteresis loops, spontaneous depolarization, and switching transients. The results of these simulations showed a good agreement with experiments and we can rationalize the obtained parameter dependencies in the framework of thermally activated nucleation limited switching (TA?NLS). The microscopic character of the model allows for a unique insight into the nucleation process of the polarization switching. We found that nucleation happens at different locations for field driven polarization switching as compared to spontaneous polarization switching. Field?driven nucleation happens at the contacts, whereas spontaneous depolarization starts at defects. This means that retention times in disordered ferroelectrics could be improved by reducing the disorder, without affecting the coercive field. Detailed analysis of the nucleation process also revealed a critical nucleation volume that decreases with applied field, which explains the Merz?like field?dependence of the switching time observed in experiments. In parallel to these microscopic simulations we developed an analytical framework based on the theory of TA?NLS. This framework is mainly focused on describing the switching transients of disordered ferroelectrics. It can be combined with concepts of the Preisach model, which considers a non?ideal ferroelectric as a collection of ideal hysterons. We were able to relate these hysterons and the distribution in their up? and down?switching fields to the microscopic structure of the material and use the combined models to explain experimentally observed dispersive switching kinetics. Whereas ferroelectrics on their own could potentially serve as memories, the readout of ferroelectric memories becomes easier if they are combined with semiconductors. We have introduced several molecular materials following the same design principle of a core?shell structure, which uniquely combine ferroelectricity and semiconductivity in one material. The experimental IV?curves of these materials could be described using an asymmetric Marcus hopping model and show their potential as memories. The combination of modeling and experimental work in this thesis thereby provides an increased understanding of organic ferroelectrics, which is crucial for their application as memories.

Quantum Chemical Investigations of Structural Parameters of PVDF based Organic Ferroelectric Materials

Quantum Chemical Investigations of Structural Parameters of PVDF based Organic Ferroelectric Materials Book
Author : Ortiz Elba,Cortes- Romero Carlos,Cuan Angeles,NoreÑa Luis,Wang Qing
Publisher : Unknown
Release : 2010
ISBN : 9789533074399
Language : En, Es, Fr & De

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Book Description :

Download Quantum Chemical Investigations of Structural Parameters of PVDF based Organic Ferroelectric Materials book written by Ortiz Elba,Cortes- Romero Carlos,Cuan Angeles,NoreÑa Luis,Wang Qing, available in PDF, EPUB, and Kindle, or read full book online anywhere and anytime. Compatible with any devices.

Ferroelectric Ceramics

Ferroelectric Ceramics Book
Author : Setter,Colla
Publisher : Birkhäuser
Release : 2012-12-06
ISBN : 3034875517
Language : En, Es, Fr & De

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Book Description :

One of the fascinating aspects of the field of ferroelectric ceramics is its interdisciplinary nature. This aspect is also a source of difficulty for the people working in the field. In a successful team of ferroelectricians the physics theoretician must understand the sintering technologist, the electrical engineer has to communicate with the crystallographer, the organic chemist will interact with the microelectronics engineer, the electron microscopist should collaborate with the systems engineer. It was the purpose of the summer school on ferroelectric ceramics that took place at the Centro Stefano Franscini (ETHZ), Monte VeritA, Ascona, Switzerland, in September 1991 to help to build bridges between people from the different disciplines and to draw for them, in the form of tutorial lectures, some of the different facets of ferroelectrics. The book is a written version of this summer school. It contains the following subjects: ferroelectric materials, physics of ferroelectrics, thin films, processing of ferroelectrics and their applications. It represents a cross section of topics of current interest. Materials are presented (L. E. Cross) from the point of view of the user, i. e. the tailoring of materials for specific applications. Two reviews address the important topic of ferroelectric domains and domain walls (I. Fousek and H. Schmid). In the part devoted to theory, three subjects of current interest are presented: phase transition in thin films (D. R. Tilley), weak ferroelectrics (A. K. Tagantsev) and dielectric losses (A. K. Tagantsev).

Ferroelectric Materials

Ferroelectric Materials Book
Author : Aimé Peláiz-Barranco
Publisher : BoD – Books on Demand
Release : 2015-07-29
ISBN : 9535121472
Language : En, Es, Fr & De

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Book Description :

Ferroelectric materials receive great attention from the scientific international community because of the interesting phenomena they exhibit and their multiple applications such as transducers, capacitors, pyroelectric sensors, sonars, random access memories, etc. The demand for ferroelectric materials for technological applications enforced the in-depth research, in addition to the improvement of processing and characterization techniques. This book contains nine chapters and offers the results of several researches covering fabrication, properties, theoretical topics, and phenomena at the nanoscale.

Thin Film Physics And Devices Fundamental Mechanism Materials And Applications For Thin Films

Thin Film Physics And Devices  Fundamental Mechanism  Materials And Applications For Thin Films Book
Author : Jianguo Zhu,Xiaohong Zhu,Hong Liu,Jie Xing
Publisher : World Scientific
Release : 2021-06-18
ISBN : 9811224005
Language : En, Es, Fr & De

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Book Description :

Thin films have an extremely broad range of applications from electronics and optics to new materials and devices. Collaborative and multidisciplinary efforts from physicists, materials scientists, engineers and others have established and advanced a field with key pillars constituting (i) the synthesis and processing of thin films, (ii) the understanding of physical properties in relation to the nanometer scale, (iii) the design and fabrication of nano-devices or devices with thin film materials as building blocks, and (iv) the design and construction of novel tools for characterization of thin films.Against the backdrop of the increasingly interdisciplinary field, this book sets off to inform the basics of thin film physics and thin film devices. Readers are systematically introduced to the synthesis, processing and application of thin films; they will also study the formation of thin films, their structure and defects, and their various properties — mechanical, electrical, semiconducting, magnetic, and superconducting. With a primary focus on inorganic thin film materials, the book also ventures on organic materials such as self-assembled monolayers and Langmuir-Blodgett films.This book will be effective as a teaching or reference material in the various disciplines, ranging from Materials Science and Engineering, Electronic Science and Engineering, Electronic Materials and Components, Semiconductor Physics and Devices, to Applied Physics and more. The original Chinese publication has been instrumental in this purpose across many Chinese universities and colleges.

Multifunctional Supramolecular Organic Ferroelectrics

Multifunctional Supramolecular Organic Ferroelectrics Book
Author : Indre Urbanaviciute
Publisher : Linköping University Electronic Press
Release : 2019-10-24
ISBN : 9179299733
Language : En, Es, Fr & De

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Book Description :

Ferroelectric materials are known and valued for their multifunctionality arising from the possibility to perturb the remnant ferroelectric polarization by electric field, temperature and/or mechanical stimuli. While inorganic ferroelectrics dominate the current market, their organic counterparts may provide highly desired properties like eco-friendliness, easy processability and flexibility, concomitantly opening unique opportunities to combine multiple functionalities into a single compound that facilitates unprecedented device concepts and designs. Supramolecular organic ferroelectrics of columnar discotic type, that are the topic of this thesis, offer additional advantages related to their strong hierarchical self-assembly and easy tunability by molecular structure modifications, allowing optimization of ferroelectric characteristics and their hybridization with, e.g., semiconductivity. This not only leads to textbook ferroelectric materials that can be used as model systems to understand the general behaviour of ferroics, but also gives rise to previously unobserved effects stemming from the interplay of different functionalities. The core-shell structure of the molecules under the scope enables multiple pathways forrational design by molecular structure modification. This was firstly pursued via peripheral tail engineering on an archetypal self-assembling ferroelectric trialkylbenzene-1,3,5-tricarboxamide (BTA). We found that by shortening the alkyl chain length all the ferroelectric properties can be continuously tuned. In particular, changing the tail from C18H37 to C6H13causes an increase in depolarization activation energy (~0.8 eV to ~1.55 eV), coercive field(~25 V/?m to ~50 V/?m) and remnant polarization (~20 mC/m2 to ~60 mC/m2). The combination of the mentioned characteristics resulted in a record polarization retention time of close to 3 months at room temperature for capacitor devices of the material having the shortest alkyl chain – BTA-C6, which at the time of writing was one of the best results for liquid-crystalline ferroelectrics. Taking one step further, we experimentally demonstrated how introduction of branched-tailsubstituents results in materials with a wide operating temperature range and a data retention time of more than 10 years in thin-film solution-processed capacitor devices already atelevated temperatures with no measurable depolarization at room temperature. The observed differences between linear- and branched-tail compounds were analysed using density functional theory (DFT) and molecular dynamics (MD) simulations. We concluded that morphological factors like improved packing quality and reduced disorder, rather than electrostatic interactions or intra/inter-columnar steric hindrance, underlay the superior properties of the branched-tailed BTAs. Synergistic effects upon blending of compounds with branched and linear sidechains were shown to further improve the materials’ characteristics. Exploiting the excellent ferroelectric performance and the well-defined nanostructure of BTAs, we experimentally determined the Preisach (hysteron) distribution of BTA and confronted it to the one obtained for the semi-crystalline P(VDF:TrFE). This allowed to elucidate how the broadening of the Preisach distribution relates to the materials’ morphology. We further connected the experimental Preisach distribution to the corresponding microscopic switching kinetics. We argue that the combination of the two underlays the macroscopic dispersive switching kinetics as commonly observed for practical ferroelectrics. These insights lead to guidelines for further advancement of ferroelectric materials both for conventional and multi-bit data storage applications. Although having strong differences in the Preisach distribution, BTA and P(VDF:TrFE) both demonstrate negative piezoelectricity – a rare anomalous phenomenon which is characteristic to two-phased materials and has never been observed in small-molecular ferroelectrics. We measured a pronounced negative piezoelectric effect in a whole family of BTAs and revealed its tunability by mesogenic tail substitution and structural disorder. While the large- and small-signal strain in highly ordered thin-film BTA capacitor devices are dominated by intrinsic contributions and originates from piezostriction, rising disorder introduces additional extrinsic factors that boost the large-signal d33 up to ?20 pm/V in short-tailed molecules. Interestingly, homologues with longer mesogenic tails show a large-signal electromechanical response that is dominated by the quadratic Maxwell strain with significant mechanical softening upon polarization switching, whereas the small-signal strain remains piezostrictive. Molecular dynamics and DFT calculations both predict a positive d33 for defect-free BTA stacks. Hence, the measured negative macroscopic d33 is attributed to the presence of structural defects that enable the dimensional effect to dominate the piezoelectric response of BTA thin films. The true multifunctionality of supramolecular discotics manifests when large semiconducting cores surrounded by field-switchable strongly polar moieties are introduced in the structure. We showed how the combination of switchable dipolar side groups and the semiconducting core of the newly synthetized C3-symmetric benzotristhiophene molecule (BTTTA) leads to an ordered columnar material showing continuous tunability from injection- to bulk-limited conductivity modulation. Both these resistive switching mechanisms may lead to the next-generation high-density non-volatile rewritable memory devices with high on/off ratios and non-destructive data readout – the element that has been desperately sought after to enablefully organic flexible electronics. Utbredd elektronisering och det högst aktuella fenomenet sakernas internet (Internet of Things) ställer höga krav på nästa generations elektroniska system. Produkterna ska vara lätta att framställa med miljövänliga metoder, låg kostnadsproduktion och skalbarhet (t. ex. tryckt elektronik), återvinningsbarhet eller biologisk nedbrytbarhet (gällande engångselektronik), mekanisk flexibilitet (formbara bärbara system), kemisk stabilitet, till och med biokompatibilitet (t. ex. implanterbara system) – dessa är bara några utmaningar som den kommande tekniken behöver övervinna. Organiska material kan åstadkomma alla dessa önskade egenskaper, samtidigt som man skapar unika möjligheter att kombinera flera funktionaliteter till en enda sammansättning som underlättar nydanande komponenter och design. Ferroelektriska material kännetecknas av pyroelektriska, piezoelektriska och dielektriska egenskaper. Denna mångsidighet möjliggör icke-flyktiga minnesenheter, temperatur- och taktila sensorer, olika transduktorer och manöverdon, som alla baseras på förändringar av den ferroelektriska restpolarisationen genom fält-, temperatur- och / eller mekaniska stimuleringar. Diskformade supramolekylära organiska ferroelektriska ämnen ger ytterligare fördelar tack vare deras modifierbara molekylstrukturer och starka hierarkiska självorganisation som staplar diskarna i kolumner. På detta sätt kan lättbearbetningsbara organiska ferroelektriska material med hög restpolarisering och extrem datalagring konstrueras molekylärt. På grund av deras väldefinierade nanostrukturer kan sådana material användas som modellsystem för att förstå det allmänna beteendet hos polykristallina ferroelektriska material. De uppvisar också ensä

Ferroelectrics

Ferroelectrics Book
Author : Mickaël Lallart
Publisher : BoD – Books on Demand
Release : 2011-08-23
ISBN : 9533074531
Language : En, Es, Fr & De

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Book Description :

Ferroelectric materials have been and still are widely used in many applications, that have moved from sonar towards breakthrough technologies such as memories or optical devices. This book is a part of a four volume collection (covering material aspects, physical effects, characterization and modeling, and applications) and focuses on the underlying mechanisms of ferroelectric materials, including general ferroelectric effect, piezoelectricity, optical properties, and multiferroic and magnetoelectric devices. The aim of this book is to provide an up-to-date review of recent scientific findings and recent advances in the field of ferroelectric systems, allowing a deep understanding of the physical aspect of ferroelectricity.