Thermoelectric charge imbalance in superconducting aluminum and the development of a scanning tunneling microscope

Technical Report · Mon Oct 01 04:00:00 EDT 1984

OSTI ID:6233333

Mamin, H J

Two experiments in solid-state physics have been performed, the observation of the superconducting fountain effect and the development of a Scanning Tunneling Microscope. In the first experiment, the quasiparticle transport current induced in a superconducting aluminum film by a temperature gradient has been measured by means of the spatially decaying charge imbalance generated near the end of the sample, where the current is divergent. The magnitude and decay length of the charge imbalance are in good agreement with the predictions of a simple model that takes into account the nonuniformity of the temperature gradient. The inferred value of the thermopower in the superconducting state agrees reasonably well with the value measured in the normal state. Measurements of the decay length of the charge imbalance induced by current injection yield a value of the inelastic relaxation time tau/sub E/ of about 2 ns, which is substantially smaller than that obtained from other measurements for reasons which are not completely understood. In the second experiment, a Scanning Tunneling Microscope, an instrument first developed at IBM Zurich, has been developed at U.C. Berkeley in order to study surface structure. On uncleaned gold surfaces, a typical vertical resolution of 0.1 A and a lateral resolution of 20 to 30 A have been achieved, with one instance of lateral resolution under 10 A. 85 references, 36 figures.

• Research Organization: Lawrence Berkeley Lab., CA (USA)
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 6233333
• Report Number(s): LBL-18324; ON: DE85004108
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360104 -- Metals & Alloys-- Physical Properties
656102* -- Solid State Physics-- Superconductivity-- Acoustic
Electronic
Magnetic
Optical
& Thermal Phenomena-- (-1987)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALUMINIUM
DATA
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTRON MICROSCOPES
ELEMENTS
EXPERIMENTAL DATA
INFORMATION
METALS
MICROSCOPES
NUMERICAL DATA
PHYSICAL PROPERTIES
PHYSICS
RELAXATION
SOLID STATE PHYSICS
SPIN-LATTICE RELAXATION
SUPERCONDUCTIVITY
SUPERCONDUCTORS
TEMPERATURE GRADIENTS
TUNNEL EFFECT
ULTRALOW TEMPERATURE