This book presents selected topics on processing and properties of ferroelectric materials that are currently the focus of attention in scientific and technical research. Ferro-piezoelectric ceramics are key materials in devices for many applications, such as automotive, healthcare and non-destructive testing. As they are polycrystalline, non-centrosymmetric materials, their piezoelectricity is induced by the so-called poling process. This is based on the principle of polarization reversal by the action of an electric field that characterizes the ferroelectric materials. This book was born with the aim of increasing the awareness of the multifunctionality of ferroelectric materials among different communities, such as researchers, electronic engineers, end-users and manufacturers, working on and with ferro-piezoelectric ceramic materials and devices which are based on them. The initiative to write this book comes from a well-established group of researchers at the Laboratories of Ferroelectric Materials, Materials Science Institute of Madrid (ICMM-CSIC). This group has been working in different areas concerning thin films and bulk ceramic materials since the mid-1980s. It is a partner of the Network of Excellence on Multifunctional and Integrated Piezoelectric Devices (MIND) of the EC, in which the European Institute of Piezoelectric Materials and Devices has its origin.
This book presents selected topics on processing and properties of ferroelectric materials that are currently the focus of attention in scientific and technical research. Ferro-piezoelectric ceramics are key materials in devices for many applications, such as automotive, healthcare and non-destructive testing. As they are polycrystalline, non-centrosymmetric materials, their piezoelectricity is induced by the so-called poling process. This is based on the principle of polarization reversal by the action of an electric field that characterizes the ferroelectric materials. This book was born with the aim of increasing the awareness of the multifunctionality of ferroelectric materials among different communities, such as researchers, electronic engineers, end-users and manufacturers, working on and with ferro-piezoelectric ceramic materials and devices which are based on them. The initiative to write this book comes from a well-established group of researchers at the Laboratories of Ferroelectric Materials, Materials Science Institute of Madrid (ICMM-CSIC). This group has been working in different areas concerning thin films and bulk ceramic materials since the mid-1980s. It is a partner of the Network of Excellence on Multifunctional and Integrated Piezoelectric Devices (MIND) of the EC, in which the European Institute of Piezoelectric Materials and Devices has its origin.
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 ensällsynt negativ piezoelektricitet som är atypisk för små molekylära material och härrör från deras komplexa nanostruktur. Den verkliga multifunktionaliteten hos diskformade supramolekylära ämnen framträder när stora halvledande kärnor omgivna av starkt polära delar, som är växlingsbara via ett elektriskt fält, introduceras i strukturen. Oöverträffad resistiv omkoppling, inducerad av den asymmetriska laddningstransporten beroende på polarisationsriktningen med rekordhög datalagringstid, upptäcktes efter optimering av molekylstrukturen. Även en konceptuellt enklare resistiv omkopplingsmekanism bunden till en modulation av laddningsinjektionsbarriären genom gränssnittsdipolerna observerades. Båda dessa fenomen kan bidra till nästa generations icke-flyktiga överskrivningsbara minnesenheter med högdensitet, stora på av-förhållanden, och icke-destruktiv dataavläsning – vilket är kritiskt för att möjliggöra helt organisk flexibel elektronik.
This book summarizes current advances in the field of multifunctional perovskite materials, including information on their synthesis, characterization, and properties as well as their use in the fabrication of devices and applications. Chapters address such topics as the physiochemical properties of various perovskite materials, advances in perovskites for solar cells, and multifunctional materials and their numerous applications.
The 55 peer-reviewed papers collected here together offer a plenitude of up-to-date information on Adaptive, Active and Multifunctional Smart Materials Systems. Volume is indexed by Thomson Reuters CPCI-S (WoS). The papers are conveniently arranged into: Chapter 1: Smart Inorganic Materials Systems, Chapter 2: Stimuli Responsive Polymers and Gels, Chapter 3: Luminescent and Chromogenic Materials Systems, Chapter 4: Multifunctional Composites and Porous Materials Systems, Chapter 5: Non-Volatile Memory Devices, Chapter 6: Multiferroics, Chapter 7: Metamaterials, Chapter 8: Graphene, Chapter 9: Multifunctional Materials for Energy Harvesting, Chapter 10: Actively Moving Polymers.
This book offers extensive knowledge and characterization methods for Ultraviolet light curable piezoelectric 0-3 composites for researchers and industry. The book provides extensive research on the use of carbon-based conductive nanoparticles to improve the performance of Ultraviolet light curable piezoelectric composites, forming piezoelectric 0-0-3 composites. Materials researched include Barium Titanate (BTO), Sodium Potassium Niobate (KNN), Graphene Nanoplatelets (GNP), Multi-Walled Carbon Nanotubes (MWCNT) and Graphene Oxide (GO). A comprehensive literature review on piezoelectric 0-3 composites focuses on the main influencing factors to achieve high piezoelectric composite performance. The method to characterize the performance of piezoelectric composites using 4-point bending is adopted from literature, is characterized, and adopted for performance measurements.
This book is devoted to the systematic description of the role of microgeometry of modern piezo-active composites in the formation of their piezoelectric sensitivity. In five chapters, the authors analyse kinds of piezoelectric sensitivity for piezo-active composites with specific connectivity patterns and links between the microgeometric feature and piezoelectric response. The role of components and microgeometric factors is discussed in the context of the piezoelectric properties and their anisotropy in the composites. Interrelations between different types of the piezoelectric coefficients are highlighted. This book fills a gap in piezoelectric materials science and provides readers with data on the piezoelectric performance of novel composite materials that are suitable for sensor, transducer, hydroacoustic, energy-harvesting, and other applications.
SPECTROSCOPY FOR MATERIALS CHARACTERIZATION Learn foundational and advanced spectroscopy techniques from leading researchers in physics, chemistry, surface science, and nanoscience In Spectroscopy for Materials Characterization, accomplished researcher Simonpietro Agnello delivers a practical and accessible compilation of various spectroscopy techniques taught and used to today. The book offers a wide-ranging approach taught by leading researchers working in physics, chemistry, surface science, and nanoscience. It is ideal for both new students and advanced researchers studying and working with spectroscopy. Topics such as confocal and two photon spectroscopy, as well as infrared absorption and Raman and micro-Raman spectroscopy, are discussed, as are thermally stimulated luminescence and spectroscopic studies of radiation effects on optical materials. Each chapter includes a basic introduction to the theory necessary to understand a specific technique, details about the characteristic instrumental features and apparatuses used, including tips for the appropriate arrangement of a typical experiment, and a reproducible case study that shows the discussed techniques used in a real laboratory. Readers will benefit from the inclusion of: Complete and practical case studies at the conclusion of each chapter to highlight the concepts and techniques discussed in the material Citations of additional resources ideal for further study A thorough introduction to the basic aspects of radiation matter interaction in the visible-ultraviolet range and the fundamentals of absorption and emission A rigorous exploration of time resolved spectroscopy at the nanosecond and femtosecond intervals Perfect for Master and Ph.D. students and researchers in physics, chemistry, engineering, and biology, Spectroscopy for Materials Characterization will also earn a place in the libraries of materials science researchers and students seeking a one-stop reference to basic and advanced spectroscopy techniques.
This book helps the reader to understand the specific properties of piezoelectric ceramic resonators. It provides their theoretical description by immitance and equivalent circuit method. The nummerical modelling described is accompanied by examples of properties measured experimentally. Piezoelectric ceramic transformers are also covered, followed by a series of solved and unsolved problems prepared specially for students.
Magnetic, Ferroelectric, and Multiferroic Metal Oxides covers the fundamental and theoretical aspects of ferroics and magnetoelectrics, their properties, and important technological applications, serving as the most comprehensive, up-to-date reference on the subject. Organized in four parts, Dr. Biljana Stojanovic leads expert contributors in providing the context to understand the material (Part I: Introduction), the theoretical and practical aspects of ferroelectrics (Part II: Ferroelectrics: From Theory, Structure and Preparation to Application), magnetic metal oxides (Part III: Magnetic Oxides: Ferromagnetics, Antiferromagnetics and Ferrimagnetics), multiferroics (Part IV: Multiferroic Metal Oxides) and future directions in research and application (Part V: Future of Metal Oxide Ferroics and Multiferroics). As ferroelectric materials are used to make capacitors with high dielectric constant, transducers, and actuators, and in sensors, reed heads, and memories based on giant magnetoresistive effects, this book will provide an ideal source for the most updated information. - Addresses ferroelectrics, ferromagnetics and multiferroelectrics, providing a one-stop reference for researchers - Provides fundamental theory and relevant, important technological applications - Highlights their use in capacitors with high dielectric constant, transducers, and actuators, and in sensors, reed heads, and memories based on giant magnetoresistive effects
