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dc.contributor.advisorRoss, Jr., Joseph H.
dc.creatorChi, Ji
dc.date.accessioned2010-01-14T23:57:58Z
dc.date.accessioned2010-01-16T01:57:06Z
dc.date.available2010-01-14T23:57:58Z
dc.date.available2010-01-16T01:57:06Z
dc.date.created2007-08
dc.date.issued2009-05-15
dc.identifier.urihttps://hdl.handle.net/1969.1/ETD-TAMU-1584
dc.description.abstractAl-rich Fe-Al systems (FeAl2, Fe2 Al5 and Fe4Al13) and Al20V2Eu have complicated structures with quasicrystal-like features making these materials potentially of interest for magnetic behavior. However, there is not much work on these materials. To study the variety of magnetic properties, we use NMR, magnetic susceptibility, specific heat and other methods in this work. The microscopic electronic and magnetic properties of the Al-rich Fe-Al system and Al20V2Eu have been studied via 27Al NMR at temperatures between 4 and 500 K. The results of spin lattice relaxation rates reveal a pseudogap in Fe4Al13 and Fe2Al5 around the Fermi-level in the density of states. Besides, a square well gap with a width of 2 meV and center at Fermi energy was detected by specific heat measurements in Fe2Al5. Both Fe4 Al13 and Fe2Al5 are non-magnetic systems with dilute magnetic defects, while FeAl2 is a concentrated local magnetic moment system. In Al20V2Eu, a crossover was observed in NMR, magnetization and transport measurements. Above 40 K, Eu(2+) local magnetic moments dominate; below 40 K, a transition to a Kondo regime is observed, where the Kondo effect leads to the reduction of localized moments due to the formation of a spin-compensated Kondo cloud. With increasing magnetic field, f electrons participate more and more in excitations near the Fermi level and a heavy-Fermion state was observed through specific heat measurements at high magnetic field.en
dc.format.mediumelectronicen
dc.format.mimetypeapplication/pdf
dc.language.isoen_US
dc.subjectIntermetallicsen
dc.subjectmagnetismen
dc.subjectNMRen
dc.titleA nuclear magnetic resonance probe of Fe-Al and Al20V2Eu intermetallicsen
dc.typeBooken
dc.typeThesisen
thesis.degree.departmentPhysicsen
thesis.degree.disciplineMaterials Science and Engineeringen
thesis.degree.grantorTexas A&M Universityen
thesis.degree.nameDoctor of Philosophyen
thesis.degree.levelDoctoralen
dc.contributor.committeeMemberAgnolet, Glenn
dc.contributor.committeeMemberNaugle, Donald G.
dc.contributor.committeeMemberSchaak, Raymond E.
dc.type.genreElectronic Dissertationen
dc.type.materialtexten
dc.format.digitalOriginborn digitalen


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