<title>Properties of diamond grown from CO<formula><inf><roman>2</roman></inf></formula> containing gas chemistries</title>

Abstract

The structural, optical and mechanical properties of CVD diamond grown using chemistries on the H-CO tie line have been investigated. A microwave plasma CVD system has been used with methane and ethylene containing gas chemistries to grow free standing optical quality diamond layers. When these feed stock gases are combined with carbon dioxide and hydrogen they enable the H-CO tie line to be traversed up to the central region of the Bachmann growth diagram. The structural properties were assessed using SEM, cathodoluminescence, Raman spectroscopy and x-ray diffraction techniques. The optical properties were assessed using several techniques including measurements of spectral emissivity over a range of temperatures and the role of nitrogen impurities identified. The trends in the optical characteristics will be discussed in relation to differences in mechanical properties with a view of evaluating the viability of using oxygen-based chemistries for the fabrication of diamond components.