Date of Graduation

5-2019

Document Type

Thesis

Degree Name

Master of Science in Microelectronics-Photonics (MS)

Degree Level

Graduate

Department

Graduate School

Advisor

Salvador Barraza-Lopez

Committee Member

Z. Ryan Tian

Second Committee Member

Rick Wise

Third Committee Member

Arun Nair

Keywords

doping, magnetic, nanofiber, nanowire, titanates

Abstract

The intricate nanostructures of layered titanates are unique among nanomaterials due to their easy and inexpensive syntheses. These nanomaterials have been proven valuable for use in industries as varied as energy, water treatment, and healthcare, and can be produced at industrial scales using already existent equipment. They have complex morphology, and surface structure well suited to chemical modification and doping. However, there is a longstanding debate on their lattice structure after the doping. There is a long-unmet need to understand, using both experimental and simulation methods, how dopants alter the clay-like layered crystal structure and associated physical and chemical properties. This thesis describes a scheme to compare data extracted from computational models of a doped version of the layered titanate H2Ti3O7 with experimental data derived from doped samples. Iron and manganese dopants were simulated at different sites in the crystal structure, and structural, electronic, and magnetic properties were investigated. XRD methods (simulated and experimental) were used to examine changes in crystal structure; EDX and XPS proved useful in investigating dopant integration and looking for indicative bonds. It was determined that differences in structural models due to doping site were too miniscule to provide unambiguous matching with experiment. Further, questions arose as to the fidelity of the models to the synthesized product. Some simulated data remains to be compared, and future work should focus on scaling simulation to match more closely experimental conditions.

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