عنوان
پدید آورنده
موضوع
رده
کتابخانه
محل استقرار
NATIONAL BIBLIOGRAPHY NUMBER
Number
TLpq230746391
LANGUAGE OF THE ITEM
.Language of Text, Soundtrack etc
انگلیسی
TITLE AND STATEMENT OF RESPONSIBILITY
Title Proper
High temperature ceramic superconductors:
General Material Designation
[Thesis]
First Statement of Responsibility
M. A. Al-Shafei
Title Proper by Another Author
Oxalate co-precipitation procedure for synthesis and influence of compositional variations
.PUBLICATION, DISTRIBUTION, ETC
Name of Publisher, Distributor, etc.
King Fahd University of Petroleum and Minerals (Saudi Arabia)
Date of Publication, Distribution, etc.
1990
PHYSICAL DESCRIPTION
Specific Material Designation and Extent of Item
145
DISSERTATION (THESIS) NOTE
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
1990
SUMMARY OR ABSTRACT
Text of Note
The objectives of the present thesis were mainly directed towards the development of new preparative procedures, rather than to prepare altogether new high-Tc materials, and to study the effects of compositional variations using measurements such as X-ray Powder Diffraction (XRD), Scanning Electron Microscope (SEM), Energy Dispersive X-ray-Spectroscopy (EDX), and Resistance versus Temperature. The conditions for co-precipitation, annealing, pulverization, effects of oxygen atmosphere, reaction with porcelain crucible and other processes were optimized for various compositions. The resistance versus temperature measurements indicate Sr was the best alkaline-earth metal among Ca, Ba and Sr for the ternary La-containing ceramics since substitution or doping of Ca and/or Ba for Sr decreased the Tc of these 21-structures. The XRD, SEM, EDX and Tc measurements for both superconducting and non-superconducting samples are discussed with respect to the cell parameters, grain sizes, morphology, peak intensities, peak positions, single phase and/or multi-phase systems, transition temperature (Tc) transition width and Tc (onset). These characteristics are further related to the compositional variation in the two series of samples studied. (Abstract shortened by UMI.)
TOPICAL NAME USED AS SUBJECT
Chemistry
Chemistry
Condensation
Pure sciences
PERSONAL NAME - PRIMARY RESPONSIBILITY
M. A. Al-Shafei
ELECTRONIC LOCATION AND ACCESS
Electronic name
مطالعه متن کتاب p
[Thesis]
276903
a
Y
