Download or read book Far Infrared Conductivity of Charge Density Wave Materials and the Oxygen Isotope Effect in High T Sub C Superconductors written by and published by . This book was released on 1991 with total page 265 pages. Available in PDF, EPUB and Kindle. Book excerpt: The far infrared reflectance and conductivity of (Ta{sub 1-x}NbxSe4)2I and TaS3 have been measured to determine the origin of a huge infrared resonance that dominates the charge density wave (CDW) dynamics along with the pinned acoustic phason mode in the related materials (TaSe4)2I and K{sub 0. 3}MoO3. The measurements cover frequencies from 3 to 700cm{sup −1} and the temperature range from 15K to 300K. In the niobium-doped alloys (Ta{sub 1-x}NbxSe4)2I, the size and frequency of the giant infrared mode remain nearly constant as the impurity concentration x is increased. For TaS3, the pinned acoustic phason near 0.5cm{sup −1} dominates {var epsilon} and an additional small mode lies near 9cm{sup −1}. The latter mode is much smaller than the infrared mode in other CDW materials. These results rule out several models of a generic infrared mode'' in CDW excitations. They are compared in detail to the predictions of a recent theory attributing the infrared mode to a bound collective mode localized at impurity sites within the crystal. The transmittance of K{sub 0.3}MoO3 has been measured at 1.2K with a strong dc electric field applied across the crystal. Under these conditions, the charge density wave depins abruptly and carries large currents with near-zero differential resistance. For some samples, the low-frequency transmittance is enhanced slightly when the CDW depins. The magnitude of the oxygen isotope effect in the high-{Tc} superconductor YBa2Cu3O-- has been determined by substitution of 18O for 16O. A series of cross-exchanges was performed on high-quality polycrystalline specimens to eliminate uncertainties due to sample heat treatments and sample inhomogeneities.
Download or read book Far infrared Conductivity of Charge Density Wave Materials and the Oxygen Isotope Effect in High Tc Superconductors written by William Nance Creager and published by . This book was released on 1991 with total page 586 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1994 with total page 892 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energy Research Abstracts written by and published by . This book was released on 1990 with total page 840 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book ERDA Energy Research Abstracts written by and published by . This book was released on 1989 with total page 848 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government Reports Announcements Index written by and published by . This book was released on 1992 with total page 1246 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Phononic and Electronic Excitations in Complex Oxides Studied with Advanced Infrared and Raman Spectroscopy Techniques written by Fryderyk Lyzwa and published by Springer Nature. This book was released on 2022-10-05 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt: This PhD thesis reports on investigations of several oxide-based materials using advanced infrared and Raman spectroscopy techniques and in combination with external stimuli such as high magnetic or electric field, sptial confinement in thin film heterostructures and the radiation with UV light. This leads to new results in the fields of superconductivity, electronic polarization states and nanoscale phenomena. Among these, the observation of anomalous polar moments is of great relevance for understanding the electric-field-induced metal-to-insulator transistion; and the demonstration that confocal Raman spectroscopy of backfolded acoustic photons in metal-oxide multilayers can be used as a powerful characterization tool for monitoring their interface properties and layer thickness is an important technical development for the engineering of such functional oxide heterostructures.
Download or read book Physical Properties of High Temperature Superconductors IV written by Donald M. Ginsberg and published by World Scientific. This book was released on 1994 with total page 592 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains two chapters of direct interest for applications: The magnetic vortex states and transformations and the effects of c-axis coupling on the transport properties. In addition, the isotope effect is reviewed, since reliable data on ultra-pure samples are now available. The lattice vibrations (phonons) have been explored extensively by inelastic neutron scattering and infrared absorption and these types of data are reviewed as well. The interesting properties of the superconducting doped fullerenes are described; some of their most fundamental properties are shared by the superconducting cuprates. This book with its subject index, like the earlier three volumes in this series, will be found useful both by people entering the field and by workers who are already active in it.
Download or read book High Temperature Superconductivity written by J. Ashkenazi and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 653 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains the proceedings of the University of Miami Workshop on the subject of "Electronic Structure and Mechanisms for High Temperature Super conductivity". The workshop was held at the James L. Knight Physics Building on the campus of the University of Miami, Coral Gables, 3-9 January 1991. Some 106 scientists from 12 countries attended this workshop, most of whom presented either invited or contributed papers. The reader will find in this volume a series of papers discussing the most im portant experimental and theoretical developments as of winter/spring 1990/1991. Despite more than four years of intensive research on high-T materials, there has c been considerable controversy both with respect to the interpretation of experiment and even more so in connection with the construction of an appropriate theory. In this regard, workshops such as this, gathering scientists with many viewpoints, and varying specialization, and fostering constructive discussions, are important in the de velopment of a common ground. Of major concern in the present context were the basic physical processes involved in high-temperature superconductivity.
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 Anharmonic Properties Of High tc Cuprates Proceedings Of The International Workshop written by Dragan Mihailovic and published by World Scientific. This book was released on 1995-06-29 with total page 290 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume deals with an important aspect of the physics of high-temperature superconductors. In recent years a wealth of experimental and theoretical work has accumulated on the subject of anharmonicity in connection to either superconductivity or lattice properties of superconducting oxides. The papers, by leading experts, are the proceedings of the first workshop dedicated to dealing with these issues.
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 Oxygen Disorder Effects in High Tc Superconductors written by Ivan K. Schuller and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 229 pages. Available in PDF, EPUB and Kindle. Book excerpt: The papers in this book represent the proceedings for the International Conference on Oxygen Disorder Effects in High~Tc Superconductors, held April 18-21, 1989 at the International Centre for Theoretical Physics, Trieste, Italy. It was recognized very early in the field of ceramic superconductors that oxygen plays a crucial role as far as the physical properties of these ma terials are concerned. The preparation requires special heating and cooling cycles which allow proper uptake of oxygen, relationships were found between the oxygen concentration and the superconducting transition temperature in many of the compounds and quite recently it was recognized that many (if not all) of the compounds present oxygen ordering in the intercalating planes. Moreover, it seems that the presence of superconductivity is strongly correlated with the presence of orthorhombic phases although several groups have also claimed the presence of superconductivity in tetragonal phases. Whether oxygen ordering plays or not a crucial role for the superconductivity remains to be seen. However it is clear that the ordering of oxygens and their thermodynamic properties is an interesting subject on its own right. All these reasons led us to organize a Conference on Oxygen Disorder Effects in High-Tc Superconductors in attempt to identify unsolved problems and to have an open discussion of the presently known facts.
Download or read book Government Reports Annual Index written by and published by . This book was released on with total page 1720 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sections 1-2. Keyword Index.--Section 3. Personal author index.--Section 4. Corporate author index.-- Section 5. Contract/grant number index, NTIS order/report number index 1-E.--Section 6. NTIS order/report number index F-Z.
Download or read book Dissertation Abstracts International written by and published by . This book was released on 1992-11 with total page 668 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Electron phonon Interaction In Oxide Superconductors Proceedings Of The First Cinvestav Superconductivity Symposium written by Rafael Baquero and published by World Scientific. This book was released on 1991-12-31 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt: Contents:Lattice Vibrations of the Cuprate Superconductors (W Reichardt et al)Evidence of Strong Electron-Phonon Interaction from the Infrared Spectra of YBa2Cu3O7 (T Timusk & D B Tanner)Electron-Phonon Interaction and Infrared Spectra of High Temperature Superconductors (O V Dolgov et al)Tunneling Studies of Bimuthate and Cuprate Superconductors (J F Zasadzinski et al)Phonon Mechanism of the High Tc Superconductivity Based on the Tunneling Structure (D Shimada et al)Lattice Instabilities in High Temperature Superconductors: The X Tilt Point Energy Surface for La2-xBaxCuO4 (W E Pickett et al)Structural Instability and Strong Coupling in Oxide Superconductors (N M Plakida)On the Isotope Effect (J P Carbotte)Electron-Phonon Coupling, Oxygen Isotope Effect and Superconductivity in Ba1-xKxBio3 (C K Loong et al)Weak Coupling Theory of the High-Tc Superconductors Based on the Electron-Phonon Interaction (J Labbé)Phonon Self-Energy Effects in Migdal-Eliashberg Theory (F Marsiglio)Electron-Phonon Interaction and Superconductivity in BaxK1-xBiO3 (K Motizuki et al)The Effect of Strong Coulomb Correlations on Electron-Phonon Interactions in the Copper Oxides: Implications for Transport (J H Kim et al)Zinc Substitution Effects on the Superconducting Properties for Ld1.85Ce0.15CuO4-δ (V García-Vázquez et al)Manifestations of the e-ph Interaction: A Summary (R Baquero) Readership: Condensed matter physicists, applied physicists, chemists, electrical engineers and materials scientists. keywords:
Download or read book High Tc Superconductors written by Harald W. Weber and published by Springer. This book was released on 1988 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the past two years conferences on superconductivity have been characterized by the attendance of hundreds of scientists. Consequently, the organizers were forced to schedule numerous parallel sessions and poster presentations with an almost unsurveyable amount of information. It was, therefore, felt that a more informal get-together, providing ample time for a thourough discussion of some topics of current interest in high-temperature superconductivity, was timely and benefitial for leading scientists as well as for newcomers in the field. The present volume contains the majority of papers presented at the International Discussion Meeting on High-Tc Superconductors held at the Mauterndorf Castle in the Austrian Alps from February 7 to 11, 1988. Each subject was introduced in review form by a few invited speakers and then discussed together with the contributed poster presentations. These discussion sessions chaired by selected scientists turned out to be the highlights of the meeting, not only because all the participants truly appreciated the possibility of an information exchange, but mainly because of the magnificent job done by the discussion chairmen, John A. Mydosh (Leiden), Martin Peter (Geneva) and Ken E. Gray (Argonne). First results on the just discovered Bi-superconductors and the clarification of electron resonance experiments on (123)-compounds should be mentioned in particular. The relaxed atomosphere favoring free discussions was certainly promoted by the surroundings offered in the Mauterndorf Castle, which dates back to 1253. Poster presentations and a conference banquet in historic knight's halls are certainly not found everyday in conference routines.
