Author: William J. Keeler
Publisher:
ISBN:
Category : Superconductors
Languages : en
Pages : 0
Book Description
Studies of superconductors as a function of pressure have, until now, been concerned mainly with the bulk properties of the metals. A study of the shift of some of the microscopic properties of strong-coupling Pb with pressure has been undertaken and this thesis reports the results of this pressure study. The method of investigation used was the electron tunneling technique, where the pressure production was achieved by suspending the samples in a solid helium bath. The energy gap and phonon spectrum of Pb as reflected in the junction conductance curves were studied as a function of pressure for the first time. The average value of dT /dP from many different junctions is in agreement with published results for bulk Pb. Shifts in the predominant transverse and longitudinal phonon groups were observed. These shifts occur in the dispersive region of the two main phonon branches. Gruneisen q's of 7 ( 0 ) = 2 0 52 and y(co) = 3.32 were obtained for the phonon peak- regions., and these can be favourable compared with results from thermal expansion work. The "recombination effect" was studied and found to be smaller than predicted, and perhaps absent altogether.
Electron Tunneling Into Superconducting Lead Subjected to Hydrostatic Pressure
Author: William J. Keeler
Publisher:
ISBN:
Category : Superconductors
Languages : en
Pages : 0
Book Description
Studies of superconductors as a function of pressure have, until now, been concerned mainly with the bulk properties of the metals. A study of the shift of some of the microscopic properties of strong-coupling Pb with pressure has been undertaken and this thesis reports the results of this pressure study. The method of investigation used was the electron tunneling technique, where the pressure production was achieved by suspending the samples in a solid helium bath. The energy gap and phonon spectrum of Pb as reflected in the junction conductance curves were studied as a function of pressure for the first time. The average value of dT /dP from many different junctions is in agreement with published results for bulk Pb. Shifts in the predominant transverse and longitudinal phonon groups were observed. These shifts occur in the dispersive region of the two main phonon branches. Gruneisen q's of 7 ( 0 ) = 2 0 52 and y(co) = 3.32 were obtained for the phonon peak- regions., and these can be favourable compared with results from thermal expansion work. The "recombination effect" was studied and found to be smaller than predicted, and perhaps absent altogether.
Publisher:
ISBN:
Category : Superconductors
Languages : en
Pages : 0
Book Description
Studies of superconductors as a function of pressure have, until now, been concerned mainly with the bulk properties of the metals. A study of the shift of some of the microscopic properties of strong-coupling Pb with pressure has been undertaken and this thesis reports the results of this pressure study. The method of investigation used was the electron tunneling technique, where the pressure production was achieved by suspending the samples in a solid helium bath. The energy gap and phonon spectrum of Pb as reflected in the junction conductance curves were studied as a function of pressure for the first time. The average value of dT /dP from many different junctions is in agreement with published results for bulk Pb. Shifts in the predominant transverse and longitudinal phonon groups were observed. These shifts occur in the dispersive region of the two main phonon branches. Gruneisen q's of 7 ( 0 ) = 2 0 52 and y(co) = 3.32 were obtained for the phonon peak- regions., and these can be favourable compared with results from thermal expansion work. The "recombination effect" was studied and found to be smaller than predicted, and perhaps absent altogether.
A Study of Superconducting Lead-indium Alloys Subjected to Hydrostatic Pressure Using the Electron Tunneling Technique
Author: Howard Helge Hansen
Publisher:
ISBN:
Category : Lead-indium alloys
Languages : en
Pages : 234
Book Description
Publisher:
ISBN:
Category : Lead-indium alloys
Languages : en
Pages : 234
Book Description
Superconducting Devices & Materials
Author:
Publisher:
ISBN:
Category : Cryotrons
Languages : en
Pages : 702
Book Description
Publisher:
ISBN:
Category : Cryotrons
Languages : en
Pages : 702
Book Description
Electron Tunnelling Into Superconductive Lead-indium Alloys Subjected to Hydrostatic Pressure
Author: Peter W. Wright
Publisher:
ISBN:
Category : Hydrostatic pressure
Languages : en
Pages : 0
Book Description
An investigation of the physical properties of the superconductive lead-indium alloy system has been carried out as a function of hydro static pressure, the results of which are presented in this thesis. Samples were prepared in the form of tunnel junctions using standard vacuum deposition techniques from extremely high purity source elements. Pressure was applied to the samples by suspending them in a bath of solid helium and their conductance characteristics, through which most of the information was gained, were recorded using phase sensitive harmonic detection techniques. The chemical composition of the particular alloys investigated (Pbggln.^ an
Publisher:
ISBN:
Category : Hydrostatic pressure
Languages : en
Pages : 0
Book Description
An investigation of the physical properties of the superconductive lead-indium alloy system has been carried out as a function of hydro static pressure, the results of which are presented in this thesis. Samples were prepared in the form of tunnel junctions using standard vacuum deposition techniques from extremely high purity source elements. Pressure was applied to the samples by suspending them in a bath of solid helium and their conductance characteristics, through which most of the information was gained, were recorded using phase sensitive harmonic detection techniques. The chemical composition of the particular alloys investigated (Pbggln.^ an
A Biweekly Cryogenics Current Awareness Service
Author:
Publisher:
ISBN:
Category : Low temperature engineering
Languages : en
Pages : 632
Book Description
Publisher:
ISBN:
Category : Low temperature engineering
Languages : en
Pages : 632
Book Description
Dissertation Abstracts International
Author:
Publisher:
ISBN:
Category : Dissertations, Academic
Languages : en
Pages : 1064
Book Description
Publisher:
ISBN:
Category : Dissertations, Academic
Languages : en
Pages : 1064
Book Description
Canadian Theses
Author: National Library of Canada
Publisher:
ISBN:
Category : Dissertations, Academic
Languages : en
Pages : 634
Book Description
Publisher:
ISBN:
Category : Dissertations, Academic
Languages : en
Pages : 634
Book Description
Nuclear Science Abstracts
Author:
Publisher:
ISBN:
Category : Nuclear energy
Languages : en
Pages : 850
Book Description
Publisher:
ISBN:
Category : Nuclear energy
Languages : en
Pages : 850
Book Description
Scientific and Technical Aerospace Reports
Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 692
Book Description
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 692
Book Description
Electron Tunneling Into Superconducting Lead-bismuth Alloy Films
Author: Ng Ser Choon
Publisher:
ISBN:
Category : Energy gap (Physics)
Languages : en
Pages : 128
Book Description
Publisher:
ISBN:
Category : Energy gap (Physics)
Languages : en
Pages : 128
Book Description