Download or read book Synthesis and transport properties of 2D transition metal carbides MXenes written by Joseph Halim and published by Linköping University Electronic Press. This book was released on 2018-09-28 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the isolation and characterization of graphene, there has been a growing interest in 2D materials owing to their unique properties compared to their 3D counterparts. Recently, a family of 2D materials of early transition metal carbides and nitrides, labelled MXenes, has been discovered (Ti2CTz, Ti3C2Tz, Mo2TiC2Tz, Ti3CNTz, Ta4C3Tz, Ti4N3Tz among many others), where T stands for surface-terminating groups (O, OH, and F). MXenes are mostly produced by selectively etching A layers (where A stands for group A elements, mostly groups 13 and 14) from the MAX phases. The latter are a family of layered ternary carbides and/or nitrides and have a general formula of Mn+1AXn (n = 1-3), where M is a transition metal and X is carbon and/or nitrogen. The produced MXenes have a conductive carbide core and a non-conductive O-, OH- and/or F-terminated surface, which allows them to work as electrodes for energy storage applications, such as Li-ion batteries and supercapacitors. Prior to this work, MXenes were produced in the form of flakes of lateral dimension of about 1 to 2 microns; such dimensions and form are not suitable for electronic characterization and applications. I have synthesized various MXenes (Ti3C2Tz, Ti2CTz and Nb2CTz) as epitaxial thin films, a more suitable form for electronic and photonic applications. These films were produced by HF, NH4HF2 or LiF + HCl etching of magnetron sputtered epitaxial Ti3AlC2, Ti2AlC, and Nb2AlC thin films. For transport properties of the Ti-based MXenes, Ti2CTz and Ti3C2Tz, changing n from 1 to 2 resulted in an increase in conductivity but had no effect on the transport mechanism (i.e. both Ti3C2Tx and Ti2CTx were metallic). In order to examine whether the electronic properties of MXenes differ when going from a few layers to a single flake, similar to graphene, the electrical characterization of a single Ti3C2Tz flake with a lateral size of about 10 μm was performed. These measurements, the first for MXene, demonstrated its metallic nature, along with determining the nature of the charge carriers and their mobility. This indicates that Ti3C2Tz is inherently of 2D nature independent of the number of stacked layers, unlike graphene, where the electronic properties change based on the number of stacked layers. Changing the transition metal from Ti to Nb, viz. comparing Ti2CTz and Nb2CTz thin films, the electronic properties and electronic conduction mechanism differ. Ti2CTz showed metallic-like behavior (resistivity increases with increasing temperature) unlike Nb2CTz where the conduction occurs via variable range hopping mechanism (VRH) - where resistivity decreases with increasing temperature. Furthermore, these studies show the synthesis of pure Mo2CTz in the form of single flakes and freestanding films made by filtering Mo2CTz colloidal suspensions. Electronic characterization of free-standing films made from delaminated Mo2CTz flakes was investigated, showing that a VRH mechanism prevails at low temperatures (7 to ≈ 60 K). Upon vacuum annealing, the room temperature, RT, conductivity of Mo2CTx increased by two orders of magnitude. The conduction mechanism was concluded to be VRH most likely dominated by hopping within each flake. Other Mo-based MXenes, Mo2TiC2Tz and Mo2Ti2C3Tz, showed VRH mechanism at low temperature. However, at higher temperatures up to RT, the transport mechanism was not clearly understood. Therefore, a part of this thesis was dedicated to further investigating the transport properties of Mo-based MXenes. This includes Mo2CTz, out-of-plane ordered Mo2TiC2Tz and Mo2Ti2C3Tz, and vacancy ordered Mo1.33CTz. Magneto-transport of free-standing thin films of the Mo-based MXenes were studied, showing that all Mo-based MXenes have two transport regimes: a VRH mechanism at lower temperatures and a thermally activated process at higher temperatures. All Mo-based MXenes except Mo1.33CTz show that the electrical transport is dominated by inter-flake transfer. As for Mo1.33CTz, the primary electrical transport mechanism is more likely to be intra-flake. The synthesis of vacancy ordered MXenes (Mo1.33CTz and W1.33CTz) raised the question of possible introduction of vacancies in all MXenes. Vacancy ordered MXenes are produced by selective etching of Al and (Sc or Y) atoms from the parent 3D MAX phases, such as (Mo2/3Sc1/3)2AlC, with in-plane chemical ordering of Mo and Sc. However, not all quaternary parent MAX phases form the in-plane chemical ordering of the two M metals; thus the synthesis of the vacancy-ordered MXenes is restricted to a very limited number of MAX phases. I present a new method to obtain MXene flakes with disordered vacancies that may be generalized to all quaternary MAX phases. As proof of concept, I chose Nb-C MXene, as this 2D material has shown promise in several applications, including energy storage, photothermal cell ablation and photocatalysts for hydrogen evolution. Starting from synthetizing (Nb2/3Sc1/3)2AlC quaternary solid solution and etching both the Sc and Al atoms resulted in Nb1.33C material with a large number of vacancies and vacancy clusters. This method may be applicable to other quaternary or higher MAX phases wherein one of the transition metals is more reactive than the other, and it could be of vital importance in applications such as catalysis and energy storage.

Download or read book NBS Special Publication written by and published by . This book was released on 1978 with total page 790 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Quantum Transport Theory written by Jorgen Rammer and published by CRC Press. This book was released on 2018-05-04 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides an introduction to transport theory, the kinetic equation approach and shows the utility of Feynman diagrams in non-equilibrium quantum statistical mechanics. It is helpful for a wider audience than students of condensed matter physics and physicists in general.

Download or read book Collective Dynamics of Nonlinear and Disordered Systems written by Günter Radons and published by Springer Science & Business Media. This book was released on 2005-11-02 with total page 377 pages. Available in PDF, EPUB and Kindle. Book excerpt: Phase transitions in disordered systems and related dynamical phenomena are a topic of intrinsically high interest in theoretical and experimental physics. This book presents a unified view, adopting concepts from each of the disjoint fields of disordered systems and nonlinear dynamics. Special attention is paid to the glass transition, from both experimental and theoretical viewpoints, to modern concepts of pattern formation, and to the application of the concepts of dynamical systems for understanding equilibrium and nonequilibrium properties of fluids and solids. The content is accessible to graduate students, but will also be of benefit to specialists, since the presentation extends as far as the topics of ongoing research work.

Download or read book Condensed Systems of Low Dimensionality written by J.L. Beeby and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 811 pages. Available in PDF, EPUB and Kindle. Book excerpt: The NATO Special Programme Panel on Condensed Systems of Low Dimensionality began its work in 1985 at a time of considerable activity in the field. The Panel has since funded many Advanced Research Workshops, Advanced Study Institutes, Cooperative Research Grants and Research Visits across the breadth of its remit, which stretches from self-organizing organic molecules to semiconductor structures having two, one and zero dimensions. The funded activities, especially the workshops, have allowed researchers from within NATO countries to exchange ideas and work together at a period of development of the field when such interactions are most valuable. Such timely support has undoubtedly assisted the development of national programs, particularly in the countries of the alliance wishing to strengthen their science base. A closing Workshop to mark the end of the Panel's activities was organized in Marmaris, Turkey from April 23-27, 1990, with the same title as the Panel: Condensed systems of Low Dimensionality. This volume contains papers presented at that meeting, which sought to bring together chemists, physicists and engineers from across the spectrum of the Panel's activities to discuss topics of current interest in their special fields and to exchange ideas about the effects of low dimensionality. As the following pages show, this is a topic of extraordinary interest and challenge which produces entirely new scientific phenomena, and at the same time offers the possibility of novel technological applications.

Download or read book Publications written by United States. National Bureau of Standards and published by . This book was released on 1971 with total page 362 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Electronic Properties of Doped Semiconductors written by B.I. Shklovskii and published by Springer Science & Business Media. This book was released on 2013-11-09 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt: First-generation semiconductors could not be properly termed "doped- they were simply very impure. Uncontrolled impurities hindered the discovery of physical laws, baffling researchers and evoking pessimism and derision in advocates of the burgeoning "pure" physical disciplines. The eventual banish ment of the "dirt" heralded a new era in semiconductor physics, an era that had "purity" as its motto. It was this era that yielded the successes of the 1950s and brought about a new technology of "semiconductor electronics". Experiments with pure crystals provided a powerful stimulus to the develop ment of semiconductor theory. New methods and theories were developed and tested: the effective-mass method for complex bands, the theory of impurity states, and the theory of kinetic phenomena. These developments constitute what is now known as semiconductor phys ics. In the last fifteen years, however, there has been a noticeable shift towards impure semiconductors - a shift which came about because it is precisely the impurities that are essential to a number of major semiconductor devices. Technology needs impure semiconductors, which unlike the first-generation items, are termed "doped" rather than "impure" to indicate that the impurity levels can now be controlled to a certain extent.

Download or read book Wave Propagation written by Peter Markos and published by Princeton University Press. This book was released on 2008-04-01 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt: This textbook offers the first unified treatment of wave propagation in electronic and electromagnetic systems and introduces readers to the essentials of the transfer matrix method, a powerful analytical tool that can be used to model and study an array of problems pertaining to wave propagation in electrons and photons. It is aimed at graduate and advanced undergraduate students in physics, materials science, electrical and computer engineering, and mathematics, and is ideal for researchers in photonic crystals, negative index materials, left-handed materials, plasmonics, nonlinear effects, and optics. Peter Markos and Costas Soukoulis begin by establishing the analogy between wave propagation in electronic systems and electromagnetic media and then show how the transfer matrix can be easily applied to any type of wave propagation, such as electromagnetic, acoustic, and elastic waves. The transfer matrix approach of the tight-binding model allows readers to understand its implementation quickly and all the concepts of solid-state physics are clearly introduced. Markos and Soukoulis then build the discussion of such topics as random systems and localized and delocalized modes around the transfer matrix, bringing remarkable clarity to the subject. Total internal reflection, Brewster angles, evanescent waves, surface waves, and resonant tunneling in left-handed materials are introduced and treated in detail, as are important new developments like photonic crystals, negative index materials, and surface plasmons. Problem sets aid students working through the subject for the first time.

Download or read book Thermoelectrics and its Energy Harvesting 2 Volume Set written by David Michael Rowe and published by CRC Press. This book was released on 2018-10-03 with total page 1100 pages. Available in PDF, EPUB and Kindle. Book excerpt: Comprising two volumes, Thermoelectrics and Its Energy Harvesting reviews the vast improvements in technology and application of thermoelectric energy with a specific intention to reduce and reuse waste heat and improve novel techniques for the efficient acquisition and use of energy.Materials, Preparation, and Characterization in Thermoelectrics i

Download or read book Strongly Correlated Fermions and Bosons in Low Dimensional Disordered Systems written by Igor V. Lerner and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 405 pages. Available in PDF, EPUB and Kindle. Book excerpt: The physics of strongly correlated fermions and bosons in a disordered envi ronment and confined geometries is at the focus of intense experimental and theoretical research efforts. Advances in material technology and in low temper ature techniques during the last few years led to the discoveries of new physical of atomic gases and a possible metal phenomena including Bose condensation insulator transition in two-dimensional high mobility electron structures. Situ ations were the electronic system is so dominated by interactions that the old concepts of a Fermi liquid do not necessarily make a good starting point are now routinely achieved. This is particularly true in the theory of low dimensional systems such as carbon nanotubes, or in two dimensional electron gases in high mobility devices where the electrons can form a variety of new structures. In many of these sys tems disorder is an unavoidable complication and lead to a host of rich physical phenomena. This has pushed the forefront of fundamental research in condensed matter towards the edge where the interplay between many-body correlations and quantum interference enhanced by disorder has become the key to the understand ing of novel phenomena.

Download or read book Electron Electron Interactions in Disordered Systems written by A.L. Efros and published by Elsevier. This book was released on 2012-12-02 with total page 703 pages. Available in PDF, EPUB and Kindle. Book excerpt: ``Electron-Electron Interactions in Disordered Systems'' deals with the interplay of disorder and the Coulomb interaction. Prominent experts give state-of-the-art reviews of the theoretical and experimental work in this field and make it clear that the interplay of the two effects is essential, especially in low-dimensional systems.

Download or read book An Introduction to Condensed Matter Physics for the Nanosciences written by Arthur McGurn and published by CRC Press. This book was released on 2023-04-13 with total page 1496 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book provides an accessible introduction to the principles of condensed matter physics with a focus on the nanosciences and device technologies. The basics of electronic, phononic, photonic, superconducting, optics, quantum optics, and magnetic properties are explored, and nanoscience and device materials are incorporated throughout the chapters. Many examples of the fundamental principles of condensed matter physics are taken directly from nanoscience and device applications. This book requires a background in electrodynamics, quantum mechanics, and statistical mechanics at the undergraduate level. It will be a valuable reference for advanced undergraduates and graduate students of physics, engineering, and applied mathematics. Features Contains discussions of the basic principles of quantum optics and its importance to lasers, quantum information, and quantum computation. Provides references and a further reading list to additional scientific literature so that readers can use the book as a starting point to then follow up with a more advanced treatment of the topics covered. Requires only a basic background in undergraduate electrodynamics, quantum mechanics, and statistical mechanics.

Download or read book Scaling And Disordered Systems International Workshop And Collection Of Articles Honoring Professor Antonio Coniglio On The Occasion Of His 60th Birthday written by Mohamed Daoud and published by World Scientific. This book was released on 2002-05-30 with total page 361 pages. Available in PDF, EPUB and Kindle. Book excerpt: Investigation of the fractal and scaling properties of disordered systems has recently become a focus of great interest in research. Disordered or amorphous materials, like glasses, polymers, gels, colloids, ceramic superconductors and random alloys or magnets, do not have a homogeneous microscopic structure. The microscopic environment varies randomly from site to site in the system and this randomness adds to the complexity and the richness of the properties of these materials. A particularly challenging aspect of random systems is their dynamical behavior. Relaxation in disordered systems generally follows an unusual time-dependent trajectory. Applications of scaling and fractal concepts in disordered systems have become a broad area of interdisciplinary research, involving studies of the physics, chemistry, mathematics, biology and engineering aspects of random systems.This book is intended for specialists as well as graduate and postdoctoral students working in condensed-matter or statistical physics. It provides state-of-the-art information on the latest developments in this important and timely topic. The book is divided into three parts: Part I deals with critical phenomena, Part II is devoted to discussion of slow dynamics and Part III involves the application of scaling concepts to random systems. The effects of disorder at the mesoscopic scale as well as the latest results on the dynamical properties of disordered systems are presented. In particular, recent developments in static and dynamic scaling theories and applications of fractal concepts to disordered systems are discussed.

Download or read book Introduction to the Network Approximation Method for Materials Modeling written by Leonid Berlyand and published by Cambridge University Press. This book was released on 2013 with total page 259 pages. Available in PDF, EPUB and Kindle. Book excerpt: Introduces graduate students to the state of the art in this fast-developing field of applied mathematics.

Download or read book Springer Handbook of Electronic and Photonic Materials written by Safa Kasap and published by Springer. This book was released on 2017-10-04 with total page 1536 pages. Available in PDF, EPUB and Kindle. Book excerpt: The second, updated edition of this essential reference book provides a wealth of detail on a wide range of electronic and photonic materials, starting from fundamentals and building up to advanced topics and applications. Its extensive coverage, with clear illustrations and applications, carefully selected chapter sequencing and logical flow, makes it very different from other electronic materials handbooks. It has been written by professionals in the field and instructors who teach the subject at a university or in corporate laboratories. The Springer Handbook of Electronic and Photonic Materials, second edition, includes practical applications used as examples, details of experimental techniques, useful tables that summarize equations, and, most importantly, properties of various materials, as well as an extensive glossary. Along with significant updates to the content and the references, the second edition includes a number of new chapters such as those covering novel materials and selected applications. This handbook is a valuable resource for graduate students, researchers and practicing professionals working in the area of electronic, optoelectronic and photonic materials.

Download or read book Charge Transport in Disordered Solids with Applications in Electronics written by Sergei Baranovski and published by John Wiley & Sons. This book was released on 2006-08-14 with total page 498 pages. Available in PDF, EPUB and Kindle. Book excerpt: The field of charge conduction in disordered materials is a rapidly evolving area owing to current and potential applications of these materials in various electronic devices This text aims to cover conduction in disordered solids from fundamental physical principles and theories, through practical material development with an emphasis on applications in all areas of electronic materials. International group of contributors Presents basic physical concepts developed in this field in recent years in a uniform manner Brings up-to-date, in a one-stop source, a key evolving area in the field of electronic materials

Download or read book Localization in Disordered Systems written by Wolfgang Weller and published by Wiley-VCH. This book was released on 1988 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: