A Raman and scanning electron microscope analysis of magnetron sputtered thin-film carbon

Thin-film carbon coatings possess properties, such as extreme hardness, smoothness, and a nice glossy finish, that make them desirable for a variety of industrial and military applications. This thesis examines the Raman spectra associated with thin-films of carbon that are prepared using magnetron sputtering. The goal is to achieve a high amount of strong bonds, i.e., sp³ bonds, as in diamond, using this inexpensive and widely available deposition process. Raman spectroscopy is the chosen analytical method used for the purpose of this work, since it is non-destructive and widely available. Using Raman spectroscopy, an sp³ content of up to 77 % is determined. This suggests that it is possible to deposit thin-films of carbon that approach the properties of tetrahedral amorphous carbon, a material known for its excellent hardness and durability, using this inexpensive approach. A scanning electron microscope image of one of the thin-films of carbon is acquired and examined, conclusions regarding the transition between the underlaying titanium substrate and the thin-film of carbon being drawn. Further directions for possible research are mentioned.Applied Science, Faculty ofEngineering, School of (Okanagan)Graduat

A Raman spectroscopic analysis of thin-films of carbon

The thin-film carbon genome is often characterized in terms of the ternary phase diagram of Ferrari and Robertson [A. C. Ferrari and J. Robertson, “Interpretation of Raman spectra of disordered and amorphous carbon”, Physical Review B, vol. 61, no. 20, pp. 14095-14107, 2000]. This thesis aims to examine as to whether or not the shape and form of the Raman spectra, acquired from various forms of thin-film carbon, depends on its location within the aforementioned phase diagram. At the outset, the answer to this question remained unknown. I perform my analysis in two-parts: (1) the development of a systematic means of processing Raman spectral data, wherein all Raman spectra are treated, and (2) the determination of Raman spectral metrics associated with these thin-films of carbon, and the examination as to whether or not these metrics are related to the position of the corresponding samples within the ternary phase diagram of Ferrari and Robertson. First, six steps are identified that must be performed in order to evaluate ID/IG, namely: (1) acquisition, (2) smoothing, (3) baseline identification, (4) baseline removal, (5) peak decomposition, and (6) evaluation of ID/IG. The second aspect of this study aims to examine as to whether the form of the Raman spectrum is shaped by the location of the sample within the thin-film carbon genome, as defined by the ternary phase diagram of Ferrari and Robertson. The answer to this question is definitely yes. The identification of how the form of the Raman spectrum is related to the position of the sample within the thin-film carbon genome, as characterized through the ternary phase diagram of Ferrari and Robertson, represents an important advance in the field of thin-film carbon science, that had previously not been noted. One could speculate that if the other material properties associated with a given sample of thin-film carbon are also related to its position within the thin- film carbon genome, that these aforementioned material properties maybe related to these Raman spectral metrics. This has potential implications, both from a fundamental materials and applications perspective that will have to be explored further in the future.Applied Science, Faculty ofEngineering, School of (Okanagan)Graduat

Fine mapping of the Cepaea nemoralis shell colour and mid-banded loci using a high-density linkage map

Molluscs are a highly speciose phylum that exhibits an astonishing array of colours and patterns, yet relatively little progress has been made in identifying the underlying genes that determine phenotypic variation. One prominent example is the land snail Cepaea nemoralis for which classical genetic studies have shown that around nine loci, several physically linked and inherited together as a ‘supergene’, control the shell colour and banding polymorphism. As a first step towards identifying the genes involved, we used whole-genome resequencing of individuals from a laboratory cross to construct a high-density linkage map, and then trait mapping to identify 95% confidence intervals for the chromosomal region that contains the supergene, specifically the colour locus (C), and the unlinked mid-banded locus (U). The linkage map is made up of 215,593 markers, ordered into 22 linkage groups, with one large group making up ~27% of the genome. The C locus was mapped to a ~1.3 cM region on linkage group 11, and the U locus was mapped to a ~0.7 cM region on linkage group 15. The linkage map will serve as an important resource for further evolutionary and population genomic studies of C. nemoralis and related species, as well as the identification of candidate genes within the supergene and for the mid-banding phenotype