Joshua Gild

Abstract

Eight nanometer platinum films were fabricated via electron beam deposition upon (001) strontium titanate (STO) substrates at ambient temperature then annealed at a range of temperatures in a reducing, oxidizing, or neutral environment. The evolution of platinum film dewetting and forming distinct nanocrystals was examined with XRD, AFM, and SEM. The initial deposition showed no crystallinity for the film. Upon annealing, a (001) cube on cube epitaxy was expected due to similar lattice parameters. However, an initial weak polycrystalline Pt (111) peak formed, which then transformed into (111) texture and eventually epitaxy. This (111) epitaxial relationship was observed in all annealing environments. The oxidizing environment suffered from significant platinum loss due to the sublimation of PtO2 at high temperatures, which as not seen in other environments. Secondary crystal growth from the STO substrate was seen in oxidizing and reducing environments and possibly indicated the in-plane epitaxy of the particles. Surface terminations of SrOx were found via AES despite etching to ensure a TiO2 termination, indicating migration of Ti atoms, most likely into the bulk platinum. The formation of (111) platinum epitaxy along with an SrOx termination in various environments indicates the substrate-platinum interactions are the predominant factor in determining platinum crystallinity and other features of the system.

Library of Congress Subject Headings

Platinum--Mechanical properties; Nanocrystals--Mechanical properties

Publication Date

5-20-2015

Document Type

Thesis

Student Type

Graduate

Degree Name

Materials Science and Engineering (MS)

Advisor

Michael Pierce

Advisor/Committee Member

John-David Rocha

Advisor/Committee Member

Thomas Trabold

Comments

Physical copy available from RIT's Wallace Library at TP245.P7 G45 2015

Campus

RIT – Main Campus

Plan Codes

MSENG-MS

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