Dynamic transport measurements of vo2 thin films through the metal-to-insulator transition

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dc.contributorGupta, Arunava
dc.contributorMewes, Tim
dc.contributorMewes, Claudia K. A.
dc.contributorTownsley, Dean M.
dc.contributor.advisorLeClair, Patrick R.
dc.contributor.authorJones, Joshua Michael
dc.contributor.otherUniversity of Alabama Tuscaloosa
dc.date.accessioned2018-07-11T16:49:39Z
dc.date.available2018-07-11T16:49:39Z
dc.date.issued2018
dc.descriptionElectronic Thesis or Dissertationen_US
dc.description.abstractVO2 is a transition metal oxide material well known for its high magnitude metal-to-insulator transition (MIT) with a corresponding change in crystal structure [1]. At room temperature, VO2 is found in an insulating monoclinic phase (P21/c) that upon heating through the transition temperature (Tc, ~341 K in bulk material) changes to a metallic rutile phase (P42/mnm) [2]. The MIT can be activated thermally by heating or cooling through Tc, but has also been shown to be sensitive to electric field [3], infrared radiation [4], pressure [5], and strain [6]. The value of Tc is also highly tunable through doping [7] and growth of strained epitaxial thin films [8]. The massive 3-4 order of magnitude change in electrical resistivity (ρ) has drawn interest for possible device level applications. The transition is characterized by the coexistence of rutile metallic domains and a monoclinic insulating matrix that results in a smooth progression of the DC transport and dielectric properties as the MIT is induced. In this thesis, we present an overview of three novel transport experiments all of which involve epitaxial TiO2/VO2 films grown in a home-built low-pressure chemical vapor deposition system. The first experiment looks at the time evolution of the film resistance and capacitance as it settles for an extended period very near Tc. We report evidence that this settling process is characterized by at least two underlying relaxation processes. The second experiment involves the deposition and ferromagnetic resonance (FMR) characterization of TiO2/VO2/Ru/Py heterostructures. Our analysis indicates enhanced spin pumping into the VO2 layer when in the metallic state that is associated with an increase in the effective Gilbert damping parameter. Finally, we discuss the results of 1/f noise spectroscopy measurements collected on Hall-bar patterned VO2(100) films. We show that the processes governing noise along both crystallographic axes are identical and, in the metallic rutile state, follows a unique R-3 scaling behavior.en_US
dc.format.extent138 p.
dc.format.mediumelectronic
dc.format.mimetypeapplication/pdf
dc.identifier.otheru0015_0000001_0002990
dc.identifier.otherJones_alatus_0004D_13455
dc.identifier.urihttp://ir.ua.edu/handle/123456789/3675
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.subjectCondensed matter physics
dc.subjectMaterials science
dc.titleDynamic transport measurements of vo2 thin films through the metal-to-insulator transitionen_US
dc.typethesis
dc.typetext
etdms.degree.departmentUniversity of Alabama. Department of Physics and Astronomy
etdms.degree.disciplinePhysics
etdms.degree.grantorThe University of Alabama
etdms.degree.leveldoctoral
etdms.degree.namePh.D.
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