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In situ growth stresses in iron-platinum and iron-copper alloy

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dc.contributorMankey, Gary J.
dc.contributorChopra, Nitin
dc.contributor.advisorThompson, Gregory B.
dc.contributor.authorFu, Bianzhu
dc.contributor.otherUniversity of Alabama Tuscaloosa
dc.date.accessioned2017-02-28T22:26:40Z
dc.date.available2017-02-28T22:26:40Z
dc.date.issued2010
dc.descriptionElectronic Thesis or Dissertationen_US
dc.description.abstractIntrinsic thin film stress is evitable with the thin film deposition process and plays an important role in tuning the physical properties of thin films. In this thesis, the in situ and post growth stress evolution of the Fe-Pt and Fe-Cu alloy system was studied and correlated to the microstructure evolutions. At ambient temperature and constant deposition pressure, the growth stresses of both the Fe-Pt and Fe-Cu alloy were found to be dependent on the compositions and affected by their growth rates. The final intrinsic stress states after growth could be tuned to be either tensile, zero or compressive depending upon composition and deposition rate for similar grain sizes. This is due to the preferential segregation of one species (the more mobile element) to the grain boundaries. At elevated growth temperatures, the Fe-Pt alloy forms ordered phase while the Fe-Cu alloy forms phase separation. The magnitude of the compressive stress state is reduced as the Fe54Pt46 thin film orders in situ during growth. The compressive stress relaxation rate is increased with increasing substrate temperature or order parameter. This compressive stress reduction has been rationalized as a reduction of adatom mobility on the surface as Fe and Pt occupy specific lattice sites for L10 on each grain. The ordered nature of the grains contributes to additional chemical energy at the boundary which, upon ceasing deposition, significantly increases the stress relaxation rate. In contrary, the growth compressive stress of the Fe51Cu49 alloys in the continuous growth regime is increased with substrate temperature. This has been rationalized as the migration of adatoms to thermodynamically preferred surfaces during growth.en_US
dc.format.extent83 p.
dc.format.mediumelectronic
dc.format.mimetypeapplication/pdf
dc.identifier.otheru0015_0000001_0000278
dc.identifier.otherFu_alatus_0004M_10279
dc.identifier.urihttps://ir.ua.edu/handle/123456789/784
dc.languageEnglish
dc.language.isoen_US
dc.publisherUniversity of Alabama Libraries
dc.relation.hasversionborn digital
dc.relation.ispartofThe University of Alabama Electronic Theses and Dissertations
dc.relation.ispartofThe University of Alabama Libraries Digital Collections
dc.rightsAll rights reserved by the author unless otherwise indicated.en_US
dc.subjectEngineering, Materials Science
dc.subjectEngineering, Metallurgy
dc.titleIn situ growth stresses in iron-platinum and iron-copper alloyen_US
dc.typethesis
dc.typetext
etdms.degree.departmentUniversity of Alabama. Department of Metallurgical and Materials Engineering
etdms.degree.disciplineMetallurgical/Materials Engineering
etdms.degree.grantorThe University of Alabama
etdms.degree.levelmaster's
etdms.degree.nameM.S.

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