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dc.contributor.advisorUwakweh, Oswald
dc.contributor.authorPérez-Moyet, Richard
dc.date.accessioned2019-04-15T17:19:21Z
dc.date.available2019-04-15T17:19:21Z
dc.date.issued2008
dc.identifier.urihttps://hdl.handle.net/handle/20.500.11801/2064
dc.description.abstractThe study of superconductivity properties enhancement on MgB2 due to TaB2 doping at 2 and 5 at.% levels were carried out, in addition to the effect of atmospheric exposure on MgB2. High energy ball milling was used for the purposes of fostering mechanical alloying, generation of nanometer sized particles, and strain inducements respectively. Atmospheric exposures at the University of Puerto Rico‐Mayagüez and University of Wisconsin‐Madison, revealed critical temperature of 37.5 K and 38 K based on resistivity measurements, while the lower critical field, Hc2 were 7.9 T and 7.0 T correspondingly. The formation of MgO during processing resulted in the variable grain connectivity and hence, the measured properties differences. SPEX 8000D processed materials revealed smaller particle size and higher strains in comparison to the Pulverisette‐4 processed ones. The 5 at.% TaB2 doped MgB2 yielded the highest critical current density (Jc) corresponding to 474.1 kA/cm2 at 2 T, while 344.4 kA/cm2 for SPEX 8000D and Pulverisette‐4 materials. Correspondingly, the values of the flux pinning (Fp) deduced for the 5t.% TaB2 doped MgB2 processed with the SPEX‐8000D mill was 7.58 GN/m3 while for same level of doping processed with the Pulverisette‐4 processed material was 6.90 GN/m3. The irreversibility field (Hirr) corresponding to the field associated with the maximization of the magnetization of the materials was 8.50 T for the 5 at.% doped MgB2, while for the same level of doping processed with Pulverisette‐4 was 7.11 T.en_US
dc.description.sponsorshipNational Science Foundation under Grant No. 0351449en_US
dc.language.isoEnglishen_US
dc.titleStudy of properties enhancement of magnesium diboride (MgB2) by TaB2 doping via high energy ball millingen_US
dc.rights.licenseAll rights reserveden_US
dc.rights.holder(c) 2008 Richard Pérez-Moyeten_US
dc.contributor.committeeJiménez González, Héctor
dc.contributor.committeeJihm-Kim, Yong
dc.contributor.committeeHelllstrom, Eric E.
dc.contributor.representativePerales-Pérez, Oscar
thesis.degree.levelM.S.en_US
thesis.degree.disciplinePhysicsen_US
dc.type.thesisThesisen_US
dc.contributor.collegeCollege of Arts and Science - Scienceen_US
dc.contributor.departmentDepartment of Physicsen_US
dc.description.graduationYear2008en_US


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  • Theses & Dissertations
    Items included under this collection are theses, dissertations, and project reports submitted as a requirement for completing a degree at UPR-Mayagüez.

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