عنوان

Preparation and characterization of yttrium barium(2) copper(3) oxygen(7-x) high critical transition temperature superconductor

Number

TLpq230729704

.Language of Text, Soundtrack etc

انگلیسی

Title Proper

Preparation and characterization of yttrium barium(2) copper(3) oxygen(7-x) high critical transition temperature superconductor

General Material Designation

[Thesis]

First Statement of Responsibility

M. A.-R. Redwan

Name of Publisher, Distributor, etc.

King Fahd University of Petroleum and Minerals (Saudi Arabia)

Date of Publication, Distribution, etc.

1991

Specific Material Designation and Extent of Item

196

Dissertation or thesis details and type of degree

M.S.

Body granting the degree

King Fahd University of Petroleum and Minerals (Saudi Arabia)

Text preceding or following the note

1991

Text of Note

Superconductor samples of YBa2Cu3O7-x were prepared by two different methods. Measurements using XRD, SEM, EPMA, and four probe method indicated single phased samples with orthorhombic structure and transition temperature of 92 K. Samples were further studied by XPS and UPS techniques, where representative clean surfaces were prepared by in-situ scraping. Valence band spectra show low density of states at Fermi level and strongly hybridized O 2p and Cu 3d states. The position, shape, and satellite emission of Cu 2p indicate a mixture of Cu and Cu valencies. The O 1s two components are intrinsic and the 531 eV peak is related to oxygen hole states (O). Ba core levels show a two component structure, suggesting two principal Ba-O configurations due to oxygen vacancies. The position and shape of Y doublets indicate weak Y-O interactions. Annealling in UHV causes an increase in O vacuncies and a reduction of Cu valency. Water exposure causes the formation of hydroxides at the surface, while oxygen exposure has no significant effect.

Condensation

Pure sciences

M. A.-R. Redwan

Electronic name

p

[Thesis]

276903

a

Y