Author: Patrick Voss-de Haan
Publisher: Ibidem Press
ISBN: 9783898210249
Category : Science
Languages : en
Pages : 150
Book Description
Since their discovery in 1986, high-temperature superconductors (HTSC) are considered interesting physical systems as well as attractive candidates for a variety of technical applications. In both cases one of the key aspects to be understood is the mechanism of power dissipation, which depends primarily on vortex dynamics: the movement of magnetic flux lines in the superconductor when a transport current is applied. The present work studies vortex dynamics in experiments on two of the most prominent types of HTSC materials, YBa2Cu3O7 (YBCO) and Bi2Sr2CaCu2O8+d (BSCCO), in the limit of low and high current densities. Both, the applied transport current density and the dimensionality of the materials, strongly influence the dynamic response. For the low current limit in BSCCO this thesis concentrates on the influence of oxygen stoichiometry and in YBCO on a vortex glass phase, which indicates a true superconducting state with vanishing linear resistivity. In the high current limit, for the first time, a vortex instability is shown to exist in BSCCO, apparently arising from a fluid phase, while a similar phenomenon in YBCO reveals a clear correlation of the high-dissipative instability to the low-dissipative vortex glass phase. The author: A native of Hamburg, Germany, Patrick Voss-de Haan studied physics at Stanford University and the University of Mainz. After completing a degree in the area of atomic physics and laser spectroscopy he began his work in solid state physics and superconductors, from which this Ph.D. thesis was compiled.
Vortex Dynamics in the High-Temperature Superconductors YBa2Cu3O7 and Bi2Sr2CaCu2O8+[delta] in Low- and High-Dissipative Transport Measurement
Author: Patrick Voss-de Haan
Publisher: Ibidem Press
ISBN: 9783898210249
Category : Science
Languages : en
Pages : 150
Book Description
Since their discovery in 1986, high-temperature superconductors (HTSC) are considered interesting physical systems as well as attractive candidates for a variety of technical applications. In both cases one of the key aspects to be understood is the mechanism of power dissipation, which depends primarily on vortex dynamics: the movement of magnetic flux lines in the superconductor when a transport current is applied. The present work studies vortex dynamics in experiments on two of the most prominent types of HTSC materials, YBa2Cu3O7 (YBCO) and Bi2Sr2CaCu2O8+d (BSCCO), in the limit of low and high current densities. Both, the applied transport current density and the dimensionality of the materials, strongly influence the dynamic response. For the low current limit in BSCCO this thesis concentrates on the influence of oxygen stoichiometry and in YBCO on a vortex glass phase, which indicates a true superconducting state with vanishing linear resistivity. In the high current limit, for the first time, a vortex instability is shown to exist in BSCCO, apparently arising from a fluid phase, while a similar phenomenon in YBCO reveals a clear correlation of the high-dissipative instability to the low-dissipative vortex glass phase. The author: A native of Hamburg, Germany, Patrick Voss-de Haan studied physics at Stanford University and the University of Mainz. After completing a degree in the area of atomic physics and laser spectroscopy he began his work in solid state physics and superconductors, from which this Ph.D. thesis was compiled.
Publisher: Ibidem Press
ISBN: 9783898210249
Category : Science
Languages : en
Pages : 150
Book Description
Since their discovery in 1986, high-temperature superconductors (HTSC) are considered interesting physical systems as well as attractive candidates for a variety of technical applications. In both cases one of the key aspects to be understood is the mechanism of power dissipation, which depends primarily on vortex dynamics: the movement of magnetic flux lines in the superconductor when a transport current is applied. The present work studies vortex dynamics in experiments on two of the most prominent types of HTSC materials, YBa2Cu3O7 (YBCO) and Bi2Sr2CaCu2O8+d (BSCCO), in the limit of low and high current densities. Both, the applied transport current density and the dimensionality of the materials, strongly influence the dynamic response. For the low current limit in BSCCO this thesis concentrates on the influence of oxygen stoichiometry and in YBCO on a vortex glass phase, which indicates a true superconducting state with vanishing linear resistivity. In the high current limit, for the first time, a vortex instability is shown to exist in BSCCO, apparently arising from a fluid phase, while a similar phenomenon in YBCO reveals a clear correlation of the high-dissipative instability to the low-dissipative vortex glass phase. The author: A native of Hamburg, Germany, Patrick Voss-de Haan studied physics at Stanford University and the University of Mainz. After completing a degree in the area of atomic physics and laser spectroscopy he began his work in solid state physics and superconductors, from which this Ph.D. thesis was compiled.
Investigation of the Vortex Dynamics in the High-temperature Superconductors Bi2Sr2CaCu2O8, YBa2Cu3O7−{delta} and YBa2Cu4O8
Author: Tiziano Teruzzi
Publisher:
ISBN:
Category :
Languages : en
Pages : 175
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 175
Book Description
Frequency Dependent Investigation of the Vortex Dynamics in High Temperature Superconductors
Author: Daniel Seymour Reed
Publisher:
ISBN:
Category : Electromagnetic measurements
Languages : en
Pages : 476
Book Description
Publisher:
ISBN:
Category : Electromagnetic measurements
Languages : en
Pages : 476
Book Description
Study of Vortex Dynamics in High Temperature Superconductors Using the Corbino Geometry
Author: Ana Mazilu
Publisher:
ISBN:
Category :
Languages : en
Pages : 310
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 310
Book Description
Investigation of the vortex phase diagram and dynamics in single crystalline samples of the high temperature superconductor YBa2Cu3O7-8
Author: Stylianos Kokkaliaris
Publisher:
ISBN:
Category :
Languages : en
Pages : 191
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 191
Book Description
Vortex Dynamics in the High Temperature Superconductor YBa2Cu3O7-0 with In-plane Columnar Defects
Author: Heather Quantz
Publisher:
ISBN:
Category : High temperature superconductors
Languages : en
Pages : 80
Book Description
Publisher:
ISBN:
Category : High temperature superconductors
Languages : en
Pages : 80
Book Description
Vortex Dynamics in the High-temperature Superconductors YBa 2 Cu 3 O 7 and Bi 2 Sr 2 CaCu 2 O 8 + Delta in Low- and High-dissipative Transport Measurements
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
This thesis investigates phenomena of vortex dynamics in type II superconductors depending on the dimensionality of the flux-line system and the strength of the driving force. In the low dissipative regime of Bi_2Sr_2CaCu_2O_{8+delta} (BSCCO) the influence of oxygen stoichiometry on flux-line tension was examined. An entanglement crossover of the vortex system at low magnetic fields was identified and a comprehensive B-T phase diagram of solid and fluid phases derived. In YBa_2Cu_3O_7 (YBCO) extremely long (>100 mm) high-quality measurement bridges allowed to extend the electric-field window in transport measurements by up to three orders of magnitude. Complementing analyses of the data conclusively produced dynamic exponents of the glass transition z~9 considerably higher than theoretically predicted and previously reported. In high-dissipative measurements a voltage instability appearing in the current-voltage characteristics of type II superconductors was observed for the first time in BSCCO and shown to result from a Larkin-Ovchinnikov flux-flow vortex instability under the influence of quasi-particle heating. However, in an analogous investigation of YBCO the instability was found to appear only in the temperature and magnetic-field regime of the vortex-glass state. Rapid-pulse measurements fully confirmed this correlation of vortex glass and instability in YBCO and revealed a constant rise time (~æs).
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
This thesis investigates phenomena of vortex dynamics in type II superconductors depending on the dimensionality of the flux-line system and the strength of the driving force. In the low dissipative regime of Bi_2Sr_2CaCu_2O_{8+delta} (BSCCO) the influence of oxygen stoichiometry on flux-line tension was examined. An entanglement crossover of the vortex system at low magnetic fields was identified and a comprehensive B-T phase diagram of solid and fluid phases derived. In YBa_2Cu_3O_7 (YBCO) extremely long (>100 mm) high-quality measurement bridges allowed to extend the electric-field window in transport measurements by up to three orders of magnitude. Complementing analyses of the data conclusively produced dynamic exponents of the glass transition z~9 considerably higher than theoretically predicted and previously reported. In high-dissipative measurements a voltage instability appearing in the current-voltage characteristics of type II superconductors was observed for the first time in BSCCO and shown to result from a Larkin-Ovchinnikov flux-flow vortex instability under the influence of quasi-particle heating. However, in an analogous investigation of YBCO the instability was found to appear only in the temperature and magnetic-field regime of the vortex-glass state. Rapid-pulse measurements fully confirmed this correlation of vortex glass and instability in YBCO and revealed a constant rise time (~æs).
Vortex Dynamics in the High-temperature Superconductors
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Investigation of the Vortex Phase Diagram and Dynamics in Single Crystalline Samples of the High Temperature Superconductor YBa0!Cu0!O0!0!0!delta#.
Author: Stylianos Kokkaliaris
Publisher:
ISBN:
Category : Chemistry, Physical and theoretical
Languages : en
Pages :
Book Description
Publisher:
ISBN:
Category : Chemistry, Physical and theoretical
Languages : en
Pages :
Book Description
Vortex Dynamics in Lightly-Doped Films of High Temperature Superconductors
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
Evidence is presented supporting the view that the inductance of vortices in films is due to columnar defects. The temperature dependence of the pinning strength is dominated by thermal supercurrent or "phase" fluctuations rather than by the mean-field temperature dependence of basic superconducting quantities like the Helmholtz free energy and the magnetic penetration depth.
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
Evidence is presented supporting the view that the inductance of vortices in films is due to columnar defects. The temperature dependence of the pinning strength is dominated by thermal supercurrent or "phase" fluctuations rather than by the mean-field temperature dependence of basic superconducting quantities like the Helmholtz free energy and the magnetic penetration depth.