High- Tc oxide superconducting thin films

Thesis/Dissertation · Sun Jan 01 04:00:00 EST 1989

OSTI ID:5193856

Wu, Xindi

The author has shown that pulsed laser deposition from a single target is simple, easy, and inexpensive compared to most of the other techniques employed for preparation of high {Tc} superconducting thin films. The pulsed laser deposition process can enable preparation of thin films of complex composition with good control over the film stoichiometry. The film compositions are similar to that of the target pellet, and independent of the substrate temperature and the oxygen partial pressure in the deposition system. The as-deposited Y-Ba-Cu oxide thin films on SrTiO{sub 3} show zero resistance temperatures and critical current densities at 77 K of over 90 K and 4-5 {times} 10{sup 6} A/cm{sup 2} respectively, which are among the best results in the world. Both mass spectroscopic and x-ray absorption studies rule out the ejection of stoichiometric clusters of the material from the pellet during the laser deposition process. Instead, binary and ternary suboxides are emitted from the target pellet. It was found that a minimum energy density is needed to have stoichiometric deposition, and only the central region of the deposited film has the right composition. These results can be explained on the basis of a primary evaporation and a secondary forward-directed ejection process. High oxygen partial pressure has been found to be an important parameter for the pulsed laser deposition of as-deposited superconducting thin films with high {Tc} and J{sub c}. The problems associated with fabrication of high quality thin films of the new high {Tc} superconductors are discussed.

• Research Organization: Rutgers--the State Univ., New Brunswick, NJ (United States)
• OSTI ID: 5193856
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360201* -- Ceramics
Cermets
& Refractories-- Preparation & Fabrication
656100 -- Condensed Matter Physics-- Superconductivity
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
BARIUM OXIDES
CHALCOGENIDES
CHEMICAL COMPOSITION
COPPER COMPOUNDS
COPPER OXIDES
CRITICAL CURRENT
CURRENTS
DEPOSITION
ELECTRIC CONDUCTIVITY
ELECTRIC CURRENTS
ELECTRICAL PROPERTIES
FABRICATION
FILMS
HIGH-TC SUPERCONDUCTORS
LASERS
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
STOICHIOMETRY
SUPERCONDUCTING FILMS
SUPERCONDUCTIVITY
SUPERCONDUCTORS
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
YTTRIUM OXIDES