| David J. Smith |
| Department of Physics |
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| Our research interests include oxide and semiconductor heterostructures, magnetic thin films and multilayers, and many types of nanostructures. Semiconductor systems of interest include ternary and quaternary Group III nitride alloys for light-emitting diodes and high power devices, and II-VI alloys such as mercury-cadmium telluride for detectors of infra-red radiation. Magnetic materials being studied include oxide antiferromagnets, as well as magnetic tunnel junctions, which are based on ferromagnet-insulator-ferromagnet combinations, that have promising applications for non-volatile, high-storage-density recording media. And we are using off-axis electron holography to investigate the magnetization behavior and fringing fields associated with patterned nanostructures in addition to studies of semiconductor pn junctions and piezoelectric fields in thin films and nanowires. |
| Nanoscale Imaging of Electrostatic and Magnetic Fields | |
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Holographic phase images of slotted Co/Cu/Py spin-valve element showing remanent magnetic configurations (Kai He) |
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Observation of hole accumulation in Ge/Si core/shell nanowire using off-axis electron holography (Luying Li) |
| Failure Mechanisms for III-Nitride Devices | |
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Cross-section of GaN HEMT device showing gate-contact region (Michael Johnson) |
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Mushroom-shaped contact inclusion observed in AlInN HFET (Lin Zhou) |
| Characterization of Improved HgCdTe Detectors | |
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Cross-section electron micrograph showing CdTe(211)/ZnTe/Si(211) interface (Wenfeng Zhao) |
| Defect Reduction in Type-II Superlattice Materials | |
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Cross-section of InAs/InAsSb Type-II superlattice (Lu Ouyang) |
| Materials for Sustainable Solar Technology | |
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Burgers' circuit analysis for perfect Lomar edge dislocation observed at ZnTe/InP hetero-interface |