Zn(_x)Co(_2-x)GeO(_4) materials were prepared and the variation in structure with composition was investigated using XED, SEM and EDX analysis. Limited series of solid solution were identified at both ends of the compositional range. D C electrical measurements were carried out to characterize the variation in the resistivity of the materials with humidity. Resistivities of the order of 10(^8) Ω m were observed in dry conditions, decreasing by 4 to 5 orders of magnitude with increasing humidity. Resistivity was not found to vary greatly with composition. Resistivity was temperature dependent, increasing by 1 to 2 orders of magnitude for a 70 C decrease in temperature. A C impedance measurements were performed to gain an understanding of the mechanism of the humidity dependent conductivity. At low frequencies impedance was found to be independent of frequency and humidity dependent. At high frequencies impedance was found to be inversely proportional to frequency and independent of humidity. The break point frequency was also humidity dependent and an increase in the impedance indicated inductive-type behaviour. Complex plane representation of the impedance gave a distorted semicircle at high frequencies and a low frequency tail. At high humidities the tail appears as a straight line, inclined at approximately 45 . At medium levels of humidity a distinctive loop is apparent at the intersection between the semicircle and the tail, corresponding to the inductive behaviour indicated at the break point frequency. The impedance response was modelled by an equivalent circuit consisting of various ideal and constant phase (dispersive) elements. The proposed mechanism of humidity-dependent conductivity is due to chemisorption and physisorption of water vapour from the atmosphere at the surface of the material, It is suggested that conduction occurs by hopping of protons between cheraisorbed hydroxyl groups at low humidities, by diffusion of H(_3)O(^+) ions between the hydroxyl groups at intermediate humidities and by hopping of protons between physisorbed H(_3)O(^+) ions (Grotthus Chain reaction) at high humidities.

Thesis (Ph. D.)--University of Texas at Austin, 2006. / Vita. Includes bibliographical references.

Thesis (Ph.D)--Electrical and Computer Engineering, Georgia Institute of Technology, 2009. / Committee Chair: Cressler, John; Committee Member: Deo, Chaitanya; Committee Member: Doolittle, Alan; Committee Member: Keezer, David; Committee Member: May, Gary; Committee Member: Papapolymerou, John. Part of the SMARTech Electronic Thesis and Dissertation Collection.

This document details experiments attempting to increase the performance of metal-oxide-semiconductor field-effect-transistors (MOSFETs) which are the mainstay of the semiconductor industry. Replacing the silicon channel with an ultra-thin epitaxial germanium layer grown selectively on a silicon (100) bulk wafer is examined in detail. The gate oxide chosen for the germanium devices is a high-k gate oxide, HfO2, and the gate electrode is a metal gate, tantalum-nitride. They demonstrate large improvements in drive current and mobility over identically processed silicon PMOSFETs. In addition to the planar germanium PMOSFETs, a process has been developed for 50nm and smaller germanium P-finFETs and N and P germanium tunnel-FETs. The patterning of sub-30nm wide and 230nm tall three dimensional fins has been done with electron beam lithography and dry plasma etching. The processes to deposit high-k gate oxide and metal gates on the sub-30nm wide fins have been developed. All that remains for the production of these devices is electron beam lithography with a maximum misalignment error of 40nm. / text

Not available / text

Thesis (M. S. in Electrical Engineering)--Vanderbilt University, Aug. 2008. / Title from title screen. Includes bibliographical references.

Thesis (M.S.)--Boise State University, 2009. / Includes abstract. Includes bibliographical references (leaves 124-131).

Thesis (Ph. D.)--University of Texas at Austin, 2009. / Title from PDF title page (University of Texas Digital Repository, viewed on Sept. 11, 2009). Vita. Includes bibliographical references.

Thesis (M.S.)--Boise State University, 2009. / Title from t.p. of PDF file (viewed June 1, 2010). Includes abstract. Includes bibliographical references (leaves 124-131).

Thesis (Ph. D.)--Ohio State University, 2005. / Title from first page of PDF file. Document formatted into pages; contains xxii, 212 p.; also includes graphics. Includes bibliographical references (p. 203-212). Available online via OhioLINK's ETD Center