Date of Award

12-26-2013

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Department of Engineering Physics

First Advisor

James C. Petrosky, PhD.

Abstract

Actinide single crystals are important to the fabrication of next generation electronic devices that could possibly have radiation with the atmosphere and surroundings. Th02 single crystals were obtained previous to this work by hydrothermal synthesis. As these crystals were the first of their kind, the geometric and electric structure of the crystals needed to be extracted. The valence and conduction bands were studied in order to ascertain the band gap using ultraviolet photoemission spectroscopy (UPS) and inverse photoemission spectroscopy (IPES). The unoccupied structure was further characterized using x-ray absorption near edge structure (XANES) and relativistic, real-space Green's functions calculations. The local structure around the Th atoms was investigated using extended x-ray absorption fine structure (EXAFS). A novel Latin hypercube sampling code was developed to extract the local order structure. X-ray photoemission spectroscopy (XPS) was used to measure a surface-to-bulk level shift and extract two new shake-up satellite structures in the 4f region. A temperature dependent XPS study extracted the Debye coefficients.

AFIT Designator

AFIT-ENP-DS-13-D-02

DTIC Accession Number

ADA602538

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