Defect and terrace characterization of PtSn₄ using scanning tunneling microscopy and spectroscopy
department or school: Science, Faculty of
department or school: Physics and Astronomy, Department of
data provider: DSpace
degree campus: UBCV
creator: Warner, Ashley Nicole
issued: 2022-07-15T19:59:22Z
issued: 2022
related degree: Master of Science - MSc
degree grantor: University of British Columbia
description: Topological materials are a newly discovered class of matter where protected gapless states arise within the material band structure. Of these materials is PtSn₄, a topological semimetal with experimentally confirmed Dirac nodal arcs in its band structure. It exhibits extremely large magnetoresistance and a high residual resistivity ratio which is indicative of efficient electron transport. There are many material characteristics responsible for excellent carrier mobility such as a topological surface state or low density defects to name a few. Since materials can exhibit high mobility without being topological, it is unknown how much of the assumed high mobility of PtSn₄ is dependent on its topological features versus something else entirely. Scanning tunneling microscopy and spectroscopy is a surface sensitive technique that allows for the imaging of a conductive surface at an atomic resolution via quantum tunneling. It is an excellent tool for studying imperfect crystal lattices due to defects, characterizing cleaving terraces of materials and probing both occupied and unoccupied electron states. In this thesis, scanning tunneling microscopy and spectroscopy is used to explore PtSn₄ in detail. The structure of the pristine lattice is defined and the three different possible terrace steps are identified using differing spectroscopies as well as comparing terrace step edge heights to distances within the unit cell. One of the main goals was to explore the intrinsic defect density of the material and provide clarity to the cause of the high residual resistivity ratio. Five different types of defects are documented in both topographic and spectroscopic detail. The lattice site origins of each defect is discussed in hopes to provide a strong basis for future exploration.
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/82152
note: Defect and Terrace Characterization of PtSn4 usingScanning Tunneling Microscopy and SpectroscopybyAshley Nicole WarnerB.Sc., UC San Diego, 2018A THESIS SUBMITTED IN PARTIAL FULFILLMENTOF THE REQUIREMENTS FOR THE DEGREE OFMaster of ScienceinTHE FACULTY OF GRADUATE AND POSTDOCTORALSTUDIES(Physics)The University of British Columbia(Vancouver)July 2022© Ashley Nicole Warner, 2022The following individuals certify that they have read, and recommend to the Fac-ulty of Graduate and Postdoctoral Studies for acceptance, the thesis entitled:Defect and Terrace Characterization of PtSn4 using Scanning Tunnel-ing Microscopy and Spectroscopysubmitted by Ashley Nicole Warner in partial fulfillment of the requirements forthe degree of Master of Science in Physics.Examining Committee:Douglas Bonn, Professor, Physics and Astronomy, UBCSupervisorSarah Burke, Professor, Physics and Astronomy, UBCSupervisory Committee MemberAlannah Hallas, Professor, Physics and Astronomy, UBCSupervisory Committee MemberiiAbstractTopological materials are a newly discovered class of matter where protected gap-less states arise within the material band structure. Of these materials is PtSn4, atopological semimetal with experimentally confirmed Dirac nodal arcs in its bandstructure. It exhibits extremely large magnetoresistance and a high residual resis-tivity ratio which is indicative of efficient electron transport. There are many mate-rial characteristics responsible for excellent carrier mobility such as a topologicalsurface state or low density defects to name a few. Since materials can exhibit highmobility without being topological, it is unknown how much of the assumed highmobility of PtSn4 is dependent on its topological features versus something elseentirely.Scanning tunneling microscopy and spectroscopy is a surface sensitive tech-nique that allows for the imaging of a conductive surface at an atomic resolutionvia quantum tunneling. It is an excellent tool for studying imperfect crystal lat-tices…
has type: Thesis/Dissertation
date issued: 2022-11
is shown at: 10.14288/1.0416291
language: eng
degree discipline: Physics
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-NonCommercial-NoDerivatives 4.0 International
rights URI: http://creativecommons.org/licenses/by-nc-nd/4.0/
scholar level: Graduate
contributor: Bonn, Douglas
type: Text
identifier URI: http://hdl.handle.net/2429/82152