Download or read book Two band Superconductivity in MgB2 Thin Films written by Valeria Ferrando and published by . This book was released on 2005 with total page 129 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Handbook of Superconductivity written by David A. Cardwell and published by CRC Press. This book was released on 2022-07-05 with total page 472 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the first of three volumes of the extensively revised and updated second edition of the Handbook of Superconductivity. The past twenty years have seen rapid progress in superconducting materials, which exhibit one of the most remarkable physical states of matter ever to be discovered. Superconductivity brings quantum mechanics to the scale of the everyday world where a single, coherent quantum state may extend over a distance of metres, or even kilometres, depending on the size of a coil or length of superconducting wire. Viable applications of superconductors rely fundamentally on an understanding of this intriguing phenomena and the availability of a range of materials with bespoke properties to meet practical needs. This first volume covers the fundamentals of superconductivity and the various classes of superconducting materials, which sets the context and background for Volumes 2 and 3. Key Features: Covers the depth and breadth of the field Includes contributions from leading academics and industry professionals across the world Provides hands-on guidance to the manufacturing and processing technologies A comprehensive reference, this handbook is suitable for both graduate students and practitioners in experimental physics, materials science and multiple engineering disciplines, including electronic and electrical, chemical, mechanical, metallurgy and others.
Download or read book Investigating Two gap Superconductivity by Scanning Tunneling Spectroscopy written by Thomas W. Heitmann and published by . This book was released on 2005 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mgb2 Superconducting Wires Basics And Applications written by Rene Flukiger and published by World Scientific. This book was released on 2016-08-10 with total page 667 pages. Available in PDF, EPUB and Kindle. Book excerpt: The compendium gives a complete overview of the properties of MgB2 (Magnesium Diboride), a superconducting compound with a transition temperature of Tc = 39K, from the fundamental properties to the fabrication of multifilamentary wires and to the presentation of various applications. Written by eminent researchers in the field, this indispensable volume not only discusses superconducting properties of MgB2 compounds, but also describes known preparation methods of thin films and of bulk samples obtained under high pressure methods.A unique selling point of the book is the detailed coverage of various applications based on MgB2, starting with MRI magnets and high current cables, cooled by Helium (He) vapor. High current cables cooled by liquid hydrogen are also highlighted as an interesting alternative due to the shrinking He reserves on earth. Other pertinent subjects comprise permanent magnets, ultrafine wires for space applications and wind generator projects.
Download or read book Topics in Superconductivity Research written by Barry P. Martins and published by Nova Publishers. This book was released on 2005 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt: Superconductivity is the ability of certain materials to conduct electrical current with no resistance and extremely low losses. High temperature superconductors, such as La2-xSrxCuOx (Tc=40K) and YBa2Cu3O7-x (Tc=90K), were discovered in 1987 and have been actively studied since. In spite of an intense, world-wide, research effort during this time, a complete understanding of the copper oxide (cuprate) materials is still lacking. Many fundamental questions are unanswered, particularly the mechanism by which high-Tc superconductivity occurs. More broadly, the cuprates are in a class of solids with strong electron-electron interactions. An understanding of such "strongly correlated" solids is perhaps the major unsolved problem of condensed matter physics with over ten thousand researchers working on this topic. High-Tc superconductors also have significant potential for applications in technologies ranging from electric power generation and transmission to digital electronics. This ability to carry large amounts of current can be applied to electric power devices such as motors and generators, and to electricity transmission in power lines. For example, superconductors can carry as much as 100 times the amount of electricity of ordinary copper or aluminium wires of the same size. Many universities, research institutes and companies are working to develop high-Tc superconductivity applications and considerable progress has been made. This new volume brings together new leading-edge research in the field.
Download or read book Tunneling Spectroscopy Studies of Superconductors written by Basu Dev Oli and published by . This book was released on 2021 with total page 201 pages. Available in PDF, EPUB and Kindle. Book excerpt: In multiband superconductors, different bands at the Fermi surface contribute to the superconductivity with different magnitudes of superconducting gaps on different portions of the Fermi surface. Each band in a multiband superconductor has a condensate with an amplitude and phase that weakly interacts with the other bands' condensate. The coupling strength between the bands determines whether one or two superconducting transition temperatures are observed, and it is the key to many peculiar properties. In general, if there are two gaps of different magnitude, there are two different length scales associated with the suppression of these gaps in applied magnetic fields, for example. Therefore, effects of multigap superconductivity can be observed in superconducting vortices, which are twirls of supercurrents that are generated when a superconductor is placed in a magnetic field. Furthermore, the two superconducting order parameters in different bands are characterized by a magnitude and phase. In multiband superconductors, there are collective excitations corresponding to fluctuations of the relative phase of two order parameters, so-called the Leggett mode. The first material identified as multiband superconductor is Magnesium Diboride (MgB2) in 2001 with a critical temperature Tc of 39 K. MgB2 is a superconducting material with the highest transition temperature among all conventional BCS superconductors. It has two superconducting gaps \Delta_\pi ~ 2 meV and \Delta_\sigma\ ~ 7 meV and they arise from the existence of two bands \pi and \sigma bands of boron electrons. The discovery of superconductivity in MgB2 renewed interest in the field of multiband superconductivity. MgB2 has attracted many scientists' attention both for the fundamental importance of understanding the multiband superconductivity and possible applications such as magnets, power cables, bolometers, Josephson junction-based electronic devices, and radio-frequency cavities. Afterward, other materials have been identified as multiband superconductors such as NbSe2, the family of iron-based superconductors, heavy fermion superconductors, multilayer cuprates, borocarbides, etc. This dissertation uses tunneling experiments to highlight multiband superconductivity features in two systems, namely MgB2 thin films and ultrathin films of Pb. Further, we use multiple techniques to study a superconducting material, nitrogen-doped niobium, used for superconducting radio-frequency cavities. For the project on MgB2, MgB2/Native-Oxide/Ag planar junctions are fabricated and characterized down to 2.1 K and in the magnetic field parallel to the sample surface up to 6 Tesla. This work investigates how pairbreaking affects the magnitude and phase of the order parameter in a multiband superconductor. The tunneling spectra are analyzed in the framework of a two-band model developed by our theory collaborator Prof. Alex Gurevich, Old Dominion University. The model allows the extraction of the pair-breaking parameters among other quantities. The analysis shows that the order parameter in the ? band is quickly suppressed in the field, the ? band is cleaner than the ? band. The ratio of pairbreaking parameter in the ? band to the ? band rapidly increases at fields higher than ~0.1 T and then plateau at higher fields. This transition around 0.1 T magnetic field suggests a phase decoupling in the two bands of MgB2. Below the transition, the two bands are phase-locked, so mostly, the superconductivity in the ? band is affected, and after phase decoupling, both bands are affected by the applied field. These results are important for a basic understanding of multiband superconductors and the application implications of this material. This phase decoupling has a new and profound consequence on the superconducting state of a multiband superconductor that has been theoretically predicted and never observed experimentally. For the Pb project, ultrathin films of Pb in ultrahigh vacuum conditions are deposited by e-beam evaporation and characterized with low-temperature scanning tunneling microscopy and spectroscopy (STM/STS). The STM/STS allows measuring the electronic density of states with the highest spatial resolution down to atomic scale. The shape of a superconducting vortex core is determined by the superconducting gap and the Fermi velocity, and the STM allows to map anisotropies of these quantities spatially. The vortex cores of Pb film show a complex shape that evolves from triangular at short distances from the center to a six-fold symmetric star shape farther away from the center. These details are very subtle, and they can be highlighted only if one works within the clean limit (to avoid the averaging effect of the scattering) and by fabricating the heterostructure that pins the vortices spatially. The complex vortex core shape reflects the anisotropy of the two bands that contribute to superconductivity in this material. For the project on Niobium, cold and hot spots from nitrogen-doped Nb cutouts are characterized by low temperature scanning tunneling microscopy and spectroscopy (STM/STS) combined with X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The radiofrequency (RF) measurements of the quality factor and temperature mapping on an N-doped Nb superconducting resonator cavity are carried out at Jefferson Laboratory before cutting out the samples. This work aims to identify possible sources of excess dissipation in hot spots and relate them to the surface chemical composition and superconducting properties. The temperature mapping revealed a strong effect of the cavity cooldown rate on the intensities of hot spots and their spatial distribution, which indicates a significant contribution of trapped vortices to the RF dissipation. SEM images acquired on the cold and hot spots using a secondary electron detector show absence of residual hydride scars and niobium nitrides on their surface. Angle-resolved XPS measurements on the native surface of these samples revealed higher oxidized Nb 3d states on the N-doped Nb cold spots, which is supported by XPS depth profiles done on the samples by Argon ion sputtering. Argon ion sputtering of oxidized Nb removes oxygen preferentially from Nb2O5 and diffuses to bulk, thickening the lower oxidation state layers. The proximity theory framework's tunneling spectra analysis suggests hot spots have stronger pairbreaking due to a weakly reduced pair potential, a thicker metallic suboxide layer, and a wide distribution of the contact resistance. STM imaging of vortex cores shows a triangular vortex lattice in both samples, and the coherence length is nearly the same in hot and cold spots. The experimental data analysis suggests weakly degraded superconducting properties at the surface of hot spot regions are not the primary sources of RF losses. Instead, they are the regions where vortices nucleate first and get trapped during cooling down. These experimental techniques and findings will be crucial in helping to qualify new recipes for SRF cavity production and to boost their performance.
Download or read book Physical Properties of High Temperature Superconductors written by Rainer Wesche and published by John Wiley & Sons. This book was released on 2015-05-13 with total page 544 pages. Available in PDF, EPUB and Kindle. Book excerpt: A much-needed update on complex high-temperaturesuperconductors, focusing on materials aspects; this timely bookcoincides with a recent major break-through of the discovery ofiron-based superconductors. It provides an overview of materials aspects of high-temperaturesuperconductors, combining introductory aspects, description of newphysics, material aspects, and a description of the materialproperties This title is suitable for researchers inmaterials science, physics and engineering. Also for techniciansinterested in the applications of superconductors, e.g. asbiomagnets
Download or read book Iron Based Superconducting Thin Films written by Silvia Haindl and published by Springer Nature. This book was released on 2021-06-27 with total page 403 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a modern introduction to the growth, characterization, and physics of iron-based superconducting thin films. Iron pnictide and iron chalcogenide compounds have become intensively studied key materials in condensed matter physics due to their potential for high temperature superconductivity. With maximum critical temperatures of around 60 K, the new superconductors rank first after the celebrated cuprates, and the latest announcements on ultrathin films promise even more. Thin film synthesis of these superconductors began in 2008 immediately after their discovery, and this growing research area has seen remarkable progress up to the present day, especially with regard to the iron chalcogenides FeSe and FeSe1-xTex, the iron pnictide BaFe2-xCoxAs2 and iron-oxyarsenides. This essential volume provides comprehensive, state-of-the-art coverage of iron-based superconducting thin films in topical chapters with detailed information on thin film synthesis and growth, analytical film characterization, interfaces, and various aspects on physics and materials properties. Current efforts towards technological applications and functional films are outlined and discussed. The development and latest results for monolayer FeSe films are also presented. This book serves as a key reference for students, lecturers, industry engineers, and academic researchers who would like to gain an overview of this complex and growing research area.
Download or read book Vortices and Nanostructured Superconductors written by Adrian Crisan and published by Springer. This book was released on 2017-07-19 with total page 266 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides expert coverage of modern and novel aspects of the study of vortex matter, dynamics, and pinning in nanostructured and multi-component superconductors. Vortex matter in superconducting materials is a field of enormous beauty and intellectual challenge, which began with the theoretical prediction of vortices by A. Abrikosov (Nobel Laureate). Vortices, vortex dynamics, and pinning are key features in many of today’s human endeavors: from the huge superconducting accelerating magnets and detectors at the Large Hadron Collider at CERN, which opened new windows of knowledge on the universe, to the tiny superconducting transceivers using Rapid Single Flux Quanta, which have opened a revolutionary means of communication. In recent years, two new features have added to the intrinsic beauty and complexity of the subject: nanostructured/nanoengineered superconductors, and the discovery of a range of new materials showing multi-component (multi-gap) superconductivity. In this book, leading researchers survey the most exciting and important recent developments in the field. Topics covered include: the use of scanning Hall probe microscopy to visualize interactions of a single vortex with pinning centers; Magneto-Optical Imaging for investigating what vortex avalanches are, why they appear, and how they can be controlled; and the vortex interactions responsible for the second magnetization peak. Other chapters discuss nanoengineered pinning centers of vortices for improved current-carrying capabilities, current anisotropy in cryomagnetic devices in relation to the pinning landscape, and the new physics associated with the discovery of new superconducting materials with multi-component superconductivity. The book offers something for almost everybody interested in the field: from experimental techniques to visualize vortices and study their dynamics, to a state-of-the-art theoretical microscopic approach to multicomponent superconductivity.
Download or read book New Challenges in Superconductivity Experimental Advances and Emerging Theories written by J. Ashkenazi and published by Springer Science & Business Media. This book was released on 2006-01-24 with total page 266 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains the proceedings of the 2004 University of Miami Workshop on Unconventional Superconductivity. The workshop was the fourth in a series of successful meetings on High-T Superconductivity and C related topics, which took place at the James L. Knight Physics Building on the University of Miami campus in Coral Gables, Florida, in January 1991, 1995, 1999, and 2004. The workshop consisted of two consecutive events: 1. NATO Advanced Research Workshop (ARW) on New Challenges in Superconductivity: Experimental Advances and Emerging Theories, held on January 11-14, 2004; 2. Symposium on Emerging Mechanisms for High Temperature Superconductivity (SEMHTS), held on January 15-16, 2004. It is hard to write a balanced preface to a volume like this one, yet at least we try to offer the reader a taste of what was happening in this workshop. There were close to a hundred scientists from around the world, albeit fewer Russians than we had originally hoped for. Nevertheless, the workshop was very lively and we trust that this is demonstrated in this volume. The workshop included high-quality presentations on state of the art works, yet a key issue, discussed by many, was how homogeneous the cuprates are. STM data, as well as other reports, showed that the cuprate superconductors (SC’s) studied were inhomogeneous, especially in the underdoped regime; while experiments, like ARPES and magnetoresistance have established the existence of a Fermi Surface (FS), at least above some doping level, in the cuprates.
Download or read book The Effect of Disorder and Chemical Substitutions in the Two band Superconductivity of MgB2 written by Andrea Calzolari and published by . This book was released on 2006 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book MgB2 Superconducting Wires written by Rene Flukiger and published by World Scientific Series in Applications of Superconductivity and Related Phenomena. This book was released on 2016 with total page 640 pages. Available in PDF, EPUB and Kindle. Book excerpt: The compendium gives a complete overview of the properties of MgB2 (Magnesium Diboride), a superconducting compound with a transition temperature of Tc = 39K, from the fundamental properties to the fabrication of multifilamentary wires and to the presentation of various applications. Written by eminent researchers in the field, this indispensable volume not only discusses superconducting properties of MgB2 compounds, but also describes known preparation methods of thin films and of bulk samples obtained under high pressure methods. A unique selling point of the book is the detailed coverage of various applications based on MgB2, starting with MRI magnets and high current cables, cooled by Helium (He) vapor. High current cables cooled by liquid hydrogen are also highlighted as an interesting alternative due to the shrinking He reserves on earth. Other pertinent subjects comprise permanent magnets, ultrafine wires for space applications and wind generator projects.
Download or read book Applied Superconductivity written by Paul Seidel and published by John Wiley & Sons. This book was released on 2015-01-22 with total page 1336 pages. Available in PDF, EPUB and Kindle. Book excerpt: This wide-ranging presentation of applied superconductivity, from fundamentals and materials right up to the details of many applications, is an essential reference for physicists and engineers in academic research as well as in industry. Readers looking for a comprehensive overview on basic effects related to superconductivity and superconducting materials will expand their knowledge and understanding of both low and high Tc superconductors with respect to their application. Technology, preparation and characterization are covered for bulk, single crystals, thins fi lms as well as electronic devices, wires and tapes. The main benefit of this work lies in its broad coverage of significant applications in magnets, power engineering, electronics, sensors and quantum metrology. The reader will find information on superconducting magnets for diverse applications like particle physics, fusion research, medicine, and biomagnetism as well as materials processing. SQUIDs and their usage in medicine or geophysics are thoroughly covered, as are superconducting radiation and particle detectors, aspects on superconductor digital electronics, leading readers to quantum computing and new devices.
Download or read book Superconductivity written by Werner Buckel and published by John Wiley & Sons. This book was released on 2008-07-11 with total page 475 pages. Available in PDF, EPUB and Kindle. Book excerpt: This well-respected and established standard work, which has been successful for over three decades, offers a comprehensive introduction into the topic of superconductivity, including its latest developments and applications. The book has been completely revised and thoroughly expanded by Professor Reinhold Kleiner. By dispensing with complicated mathematical derivations, this book is of interest to both science and engineering students. For almost three decades now, the German version of this book - currently in its sixth edition - has been established as one of the state of the art works on superconductivity.
Download or read book High Temperature Superconductors written by Raghu N. Bhattacharya and published by John Wiley & Sons. This book was released on 2011-08-24 with total page 267 pages. Available in PDF, EPUB and Kindle. Book excerpt: This essential reference provides the most comprehensive presentation of state-of-the-art research being conducting worldwide today in this growing field of research and applications. HTS are currently being supported by numerous governmental and industrial initiatives in the USA and Asia and Europe to overcome energy distribution issues and are now being commercialised for power-delivery devices, such as power transmission lines and cables, motors, and generators. Applications in electric utilities include energy-storing devices to help industries avoid dips in electric power, current limiters, and long transmission lines. The technology is particularly thought out for highly-populated and densed areas. Both editors are leading experts in the field from the National Renewable Energy Laboratory and the Oak Ridge National Laboratory. This book can be used as a companion teaching tool, and also as as a research and professional reference.
Download or read book Superconductors written by A. V. Narlikar and published by Oxford University Press. This book was released on 2014-04-03 with total page 560 pages. Available in PDF, EPUB and Kindle. Book excerpt: Superconductors is neither about basic aspects of superconductivity nor about its applications, but its mainstay is superconducting materials. Unusual and unconventional features of a large variety of novel superconductors are presented and their technological potential as practical superconductors assessed. The book begins with an introduction to basic aspects of superconductivity. The presentation is readily accessible to readers from a diverse range of scientific and technical disciplines, such as metallurgy, materials science, materials engineering, electronic and device engineering, and chemistry. The derivation of mathematical formulas and equations has been kept to a minimum and, wherever necessary, short appendices with essential mathematics have been added at the end of the text. The book is not meant to serve as an encyclopaedia, describing each and every superconductor that exists, but focuses on important milestones in their exciting development.
Download or read book Endless Quests Theory Experiments And Applications Of Frontiers Of Superconductivity written by Jiangdi Fan and published by World Scientific. This book was released on 2019-01-15 with total page 325 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book is devoted to advancing and developing the frontiers of superconductivity; in particular, the theory of the Diagrammatic Iteration Approach (DIA), described in Chapter 1, is unique in the community of superconductivity.The application of DIA to electron correlation effects has allowed the tough issue of strongly-coupled electron systems to be solved, which is important for high-temperature superconductivity (HTS). DIA, when applied to a layered two-dimensional system, gives rise to marvelous outcomes that can explain all the anomalies in the normal state of HTS, and leads to a transition temperature that is dependent on quantities including the dielectric constant, electron band mass and spacing between layers. This then serves as a quantifiable guide on how to make ideal superconductors. Moreover, in such a scenario, the mechanisms of low- and high-temperature superconductivity can be unified on the basis of repulsive Coulomb interactions between electrons.The book contains rich first-hand information on experiments at the frontiers of superconductivity, as well as on relevant applications of such cutting-edge developments. For instance, Jiasu Wang, co-author of the chapter discussing the HTS Maglev train, is the person who completed the world's first HTS Maglev train. Thus, the draw of this book lies not only in its ability to marry theory, experiment and application, but also in its inclusion of research from prestigious experts of the field.
