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Doctoral Dissertation Announcement
Candidate: Elias Garratt
Doctor of Philosophy
Title: Compositional and Structural Analysis of Nitrogen Incorporated and Ion Implanted Diamond Thin Films
Dr. Asghar Kayani, Chair
Dr. John Tanis
Dr. Clement Burns
Dr. Muralidhar Ghantasala
Date: Thursday, October 25, 2012 2:00 p.m. to 4:00 p.m.
2202 Everett Tower
Significant progress in the area of nano-structured thin film systems has taken place in recent decades. In particular, diamond thin film systems are being widely studied for their wear resistant, optical and electronic properties. Of the various methods researchers use to modify the structure of such films, three techniques in particular are of interest due to their versatility: modification of growth atmosphere, interfacial layer and modification through post-growth ion implantation. The aim of this study is to investigate the effects each has to the structure and composition of elements. Different techniques are applied in each section; nitrogen gas dilution in a microwave plasma CVD system, diamond deposition on a metal interfacial layer and ion implantation in thin nanocrystalline diamond film. The forms of nanocrystalline diamond film resulting from such modifications are investigated using advanced spectroscopic and spectrometric techniques, as well as mechanical testing and surface mapping.
In the field of materials physics, to obtain a complete picture of the system at hand one must study it from various perspectives using complementary techniques. Within this study ion beam analysis techniques correlate with x-ray and optical spectroscopic techniques to develop a picture of the structure within complex interfacial layers, while surface mapping and hardness tests reveal their mechanical properties. Resonant nuclear reaction analysis is used to probe the specific content and depth profile of nitrogen within nanocrystalline diamond film. This data is then correlated with secondary ion mass spectrometry. Transmission electron microscopy and electron spectroscopy are used to reveal heavy ion implantation effects in nanocrystalline diamond microstructure in correlation with surface mapping. A striking difference between the layer just below the surface of the film versus the surface itself illustrates the selective nature of the ion implantation technique, which can be applied towards engineering uniquely layered films.
The impact of these characterizations will provide valuable perspective to researchers in materials science. Understanding the changes to the structures and properties of this class of thin films, which can be induced through various mechanisms, will allow future researchers to refine these films towards technological applications in areas of hard coatings, electronics and photonics.