| dc.contributor.advisor |
Markert, John T. |
| dc.creator |
Park, Keeseong, 1972-
|
| dc.date.accessioned |
2008-08-28T23:36:15Z |
| dc.date.available |
2008-08-28T23:36:15Z |
| dc.date.created |
2007 |
| dc.date.issued |
2008-08-28T23:36:15Z |
| dc.identifier.uri |
http://hdl.handle.net/2152/3242 |
| dc.description.abstract |
Oxygen hole-doping effects on a spin-chain system, Ca[subscript 2+chi]Y[2-chi]Cu₅O[subscript 10-delta](CaYCuO) are reported. CaYCuO is a good specimen to study the magnetic properties of the CuO₂ chain at the ground state because it has no complex structure other than the chain and it has hole dopability up to the formal copper valence number of +2.4. Specifically, we can dope holes into the CuO₂ chain by substituting Ca²⁺ for Y³⁺ or by utilizing oxygen deficiency. After a systematic study of the two methods to dope holes, we found that oxygen doping makes a more critical change in magnetic ordering in the chain than the replacement of Ca²⁺. Oxygen deficiency effects of the chain on the magnetic properties were explained using a mean field theory. A new relation for the effective hole doping was found as p = x - [alpha delta], where a = 3/2(x - [delta]) - 1/4. We study the anisotropy of magnetic properties of single crystal Li-cathode material (LiFePO₄) for g-factor, Curie-Weiss temperature, and effective moment. Magnetic properties Au/SiO₂ coated [gamma]-Fe₂O₃ are compared with pure [gamma]-Fe₂O₃ finding a decrease in the blocking temperature and the irreversible temperature for the coated nanoparticles. |
| dc.format.medium |
electronic |
| dc.language.iso |
eng |
| dc.rights |
Copyright © is held by the author. Presentation of this material on
the Libraries' web site by University Libraries, The University of Texas at Austin was made
possible under a limited license grant from the author who has retained all copyrights in
the works. |
| dc.subject.lcsh |
Oxygen--Industrial applications
|
| dc.subject.lcsh |
Copper oxide superconductors
|
| dc.subject.lcsh |
Minerals--Magnetic properties
|
| dc.title |
Magnetic phase diagram of Ca₂₊xY₂₋xCu₅O₁₀₋[delta]: oxygen hole-doping effects |
| dc.description.department |
Physics
|
| dc.identifier.oclc |
174113855 |
| dc.identifier.recnum |
b68890060 |
| dc.type.genre |
Thesis |
| dc.type.material |
text |
| thesis.degree.department |
Physics
|
| thesis.degree.discipline |
Physics |
| thesis.degree.grantor |
The University of Texas at Austin |
| thesis.degree.level |
Doctoral |
| thesis.degree.name |
Doctor of Philosophy |
