Download or read book Spectroscopic Studies of High temperature Superconductors on Planar Tunnel Junction Devices and Nanofabricated Point Contact Junctions written by Han Zhao and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 High Temperature Superconductors written by X G Qiu and published by Elsevier. This book was released on 2011-03-28 with total page 450 pages. Available in PDF, EPUB and Kindle. Book excerpt: High temperature superconductors have received a great deal of attention in recent years, due to their potential in device and power applications. This book summarises the materials science and physics of all the most important high temperature superconductors as well as discussing material growth, properties and applications. Part one covers fundamental characteristics of high temperature superconductors and high TC films such as deposition technologies, growth, transport properties and optical conductivity. Part two is concerned with growth techniques and properties of high temperature superconductors, including YBCO, BSCCO and HTSC high TC films, and electron-doped cuprates. Finally, part three describes the various applications of high temperature superconductors, from Josephson junctons and dc-superconductive quantum inference devices (dc-SQUIDs) to microwave filters. With its distinguished editor and international team of contributors, this book is an invaluable resource for those researching high temperature superconductors, in industry and academia. In light of the many recent advances in high temperature superconductors, it will benefit physicists, materials scientists and engineers working in this field, as well as in areas of industrial application, such as electronic devices and power transmission. Summarises the materials science and physics of all the most important high temperature superconductors Discusses material growth, properties and applications Outlines fundamental characteristics of high temperature superconductors and high TC films
Download or read book Scanning Probe Microscopy Characterization Nanofabrication and Device Application of Functional Materials written by Paula Maria Vilarinho and published by Springer Science & Business Media. This book was released on with total page 530 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Studies of High Temperature Superconductors written by A. V. Narlikar and published by Nova Publishers. This book was released on 1993 with total page 476 pages. Available in PDF, EPUB and Kindle. Book excerpt: Six papers by physicists from the Japan, India, Brazil and the US address some of the broad frontal issues of superconductivity, which include the mechanisms of high-temperature superconductivity, extra-high-temperature phenomena, the normal state pseudogap, the observations of the isotope effect in a host of different superconducting systems and their explanations, and the unusual features of strongly correlated electron systems like heavy fermions. Two extended papers explore the importance of positron annihilation and using electron spin resonance techniques to study superconducting materials. The treatments should be accessible to working scientists and engineers and to graduate students of physics, chemistry, materials science, solid-state electronics, and other disciplines.
Download or read book Electron Tunneling and Point Contact Andreev Reflection Studies of Superconductors written by Wenqing Dai and published by . This book was released on 2014 with total page 155 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book HTS Thin Film and More on Vortex Studies written by A. V. Narlikar and published by Nova Publishers. This book was released on 2005 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: HTS Thin Film & More On Vortex Studies - Advances in Research & Applications
Download or read book Studies of High Temperature Superconductors written by Anant Narlikar and published by Nova Publishers. This book was released on 1999 with total page 266 pages. Available in PDF, EPUB and Kindle. Book excerpt: Studies Of High Temperature Superconductors Volume 29 -- Advances In Research & Applications
Download or read book Physics and Materials Science of High Temperature Superconductors II written by R. Kossowsky and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 798 pages. Available in PDF, EPUB and Kindle. Book excerpt: Physics and Materials Science of High Temperature Superconductors, II represents the results of a fruitful dialogue between physicists and materials scientists which took place under the auspices of a NATO Advanced Study Institute in Porto Carras, Greece, between 18 and 31 August, 1991. It builds on and carries forward the success of NATO ASI 181 published in 1990. The theoretical side of the discussions reveal the basic premise of the phenomenological and Ginzburg-Landau theories of superconductivity, the implications of short coherence length, long penetration depth, the melting of flux lattices, and other matters, while the materials science includes discussions of microstructures, local inhomogeneities, deviations from ideal chemistry, the effects of systematic errors in materials preparation, the definition of imperfections, and the utilization of common materials analysis techniques. The reader will be made aware of the potential significance of Angstrom scale structural and chemical details, and the need to consider basic theoretical concepts when designing procedures to process viable, solid conductors, specifically the effects of oxygen stoichiometry and deviations from it, as well as the microstructural demands on pinning in the light of very short coherence lengths.
Download or read book Handbook of High Temperature Superconductor written by Neeraj Khare and published by CRC Press. This book was released on 2003-05-06 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt: Devoted to the preparation, characterization and evaluation of HTS electronic devices, the Handbook of High-Temperature Superconductor Electronics provides information on using high-Tc thin films and junctions to increase speed, lessen noise, lower power consumption and enhance upper frequency limits in superconductor electronics. Compiled by a gro
Download or read book Angle Resolved Photoemission Spectroscopy on High Temperature Superconductors written by Junfeng He and published by Springer. This book was released on 2016-06-21 with total page 137 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book mainly focuses on the study of the high-temperature superconductor Bi2Sr2CaCu2O8+δ (Bi2212) and single-layer FeSe film grown on SrTiO3 (STO) substrate by means of angle-resolved photoemission spectroscopy (ARPES). It provides the first electronic evidence for the origin of the anomalous high-temperature superconductivity in single-layer FeSe grown on SrTiO3 substrate. Two coexisted sharp-mode couplings have been identified in superconducting Bi2212. The first ARPES study on single-layer FeSe/STO films has provided key insights into the electronic origin of superconductivity in this system. A phase diagram and electronic indication of high Tc and insulator to superconductor crossover have been established in the single-layer FeSe/STO films. Readers will find essential information on the techniques used and interesting physical phenomena observed by ARPES.
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 Superconductors at the Nanoscale written by Roger Wördenweber and published by Walter de Gruyter GmbH & Co KG. This book was released on 2017-09-11 with total page 590 pages. Available in PDF, EPUB and Kindle. Book excerpt: By covering theory, design, and fabrication of nanostructured superconducting materials, this monograph is an invaluable resource for research and development. Examples are energy saving solutions, healthcare, and communication technologies. Key ingredients are nanopatterned materials which help to improve the superconducting critical parameters and performance of superconducting devices, and lead to novel functionalities. Contents Tutorial on nanostructured superconductors Imaging vortices in superconductors: from the atomic scale to macroscopic distances Probing vortex dynamics on a single vortex level by scanning ac-susceptibility microscopy STM studies of vortex cores in strongly confined nanoscale superconductors Type-1.5 superconductivity Direct visualization of vortex patterns in superconductors with competing vortex-vortex interactions Vortex dynamics in nanofabricated chemical solution deposition high-temperature superconducting films Artificial pinning sites and their applications Vortices at microwave frequencies Physics and operation of superconducting single-photon devices Josephson and charging effect in mesoscopic superconducting devices NanoSQUIDs: Basics & recent advances Bi2Sr2CaCu2O8 intrinsic Josephson junction stacks as emitters of terahertz radiation| Interference phenomena in superconductor-ferromagnet hybrids Spin-orbit interactions, spin currents, and magnetization dynamics in superconductor/ferromagnet hybrids Superconductor/ferromagnet hybrids
Download or read book Photoemission Spectroscopy on High Temperature Superconductor written by Wentao Zhang and published by Springer Science & Business Media. This book was released on 2012-08-22 with total page 147 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book mainly focuses on the study of the high-temperature superconductor Bi2Sr2CaCu2O8 by vacuum, ultra-violet, laser-based, angle-resolved photoemission spectroscopy (ARPES). A new form of electron coupling has been identified in Bi2212, which occurs in the superconducting state. For the first time, the Bogoliubov quasiparticle dispersion with a clear band back-bending has been observed with two peaks in the momentum distribution curve in the superconducting state at a low temperature. Readers will find useful information about the technique of angle-resolved photoemission and the study of high-temperature superconductors using this technique. Dr. Wentao Zhang received his PhD from the Institute of Physics at the Chinese Academy of Sciences.
Download or read book Physical Properties Of High Temperature Superconductors Iii written by Donald M Ginsberg and published by World Scientific. This book was released on 1992-03-03 with total page 642 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume brings the reader up to date on transport phenomena, including electrical and thermal conductivity and infrared properties. In addition, electron tunneling and the characteristics and applications of films are discussed; the preparation of the necessary samples has proceeded, and a sizeable body of reproducible data has become available. Pressure effects are also presented; considerable progress has been made in relating them to the crystallographic and electronic structure of high temperature superconductors. The preparation and characterization of bulk samples is also reviewed.
Download or read book Point Contact Spectroscopy with Nanofabricated Junctions of Spin and Energy dependent Transport in Heterogeneous Ferromagnetic Systems written by Richard Nam Louie and published by . This book was released on 1997 with total page 770 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Charge Dynamics in 122 Iron Based Superconductors written by Aliaksei Charnukha and published by Springer Science & Business Media. This book was released on 2013-09-12 with total page 139 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis combines highly accurate optical spectroscopy data on the recently discovered iron-based high-temperature superconductors with an incisive theoretical analysis. Three outstanding results are reported: (1) The superconductivity-induced modification of the far-infrared conductivity of an iron arsenide with minimal chemical disorder is quantitatively described by means of a strong-coupling theory for spin fluctuation mediated Cooper pairing. The formalism developed in this thesis also describes prior spectroscopic data on more disordered compounds. (2) The same materials exhibit a sharp superconductivity-induced anomaly for photon energies around 2.5 eV, two orders of magnitude larger than the superconducting energy gap. The author provides a qualitative interpretation of this unprecedented observation, which is based on the multiband nature of the superconducting state. (3) The thesis also develops a comprehensive description of a superconducting, yet optically transparent iron chalcogenide compound. The author shows that this highly unusual behavior can be explained as a result of the nanoscopic coexistence of insulating and superconducting phases, and he uses a combination of two complementary experimental methods - scanning near-field optical microscopy and low-energy muon spin rotation - to directly image the phase coexistence and quantitatively determine the phase composition. These data have important implications for the interpretation of data from other experimental probes.
