Title: Fabrication and Characterization of Chalcogenide and Oxide Thin Films
Abstract: This dissertation explores the fabrication, structural characterization, and quantum transport properties of chalcogenide and oxide thin films. High-quality SnTe films were synthesized via molecular beam epitaxy (MBE), demonstrating tunable topological surface states through nanoscale patterning. Magnetoconductivity measurements revealed weak antilocalization (WAL) effects across continuous and patterned films, with coherence lengths governed by boundary scattering in hole-patterned geometries. Advanced focused ion beam (FIB) protocols enabled atomic-resolution transmission electron microscopy (TEM) of monolayer ZrO2 on silicon, defect distribution in off-stoichiometric CaWO4 films and phase analysis in YVO4 thin films. Josephson junctions fabricated on superconducting Nd1-xEuxNiO2 thin films exhibited macroscopic quantum transport behavior. By integrating nanofabrication with multi-scale characterization, this work establishes design principles for investigating quantum phenomena in low-dimensional systems, advancing applications in topological electronics and superconducting devices.
Defense Committee: Charles Ahn (advisor), Frederick Walker, Yu He, Cong Su, and Stephen Albright (external)