form of silicon carbide introduced in 1998 as an alternative to diamonds, which has a similar thermal conductivity. Technologically, the high thermal conductivity of diamond is used for the efficient heat removal in high-end power electronics. Diamond is especially appealing in situations where electrical conductivity of the heat sinking material cannot be tolerated e.g. for the thermal management of high-power radio-frequency () microcoils that are used to produce strong and local RF fields. Thermal stability Being a form of carbon, diamond oxidizes in air if heated over . In absence of oxygen, e.g. in a flow of high-purity argon gas, diamond can be heated up to about . Its surface blackens, but can be recovered by re-polishing. At high pressure (~) diamond can be heated up to , and a report published in 2009 suggests that diamond can withstand temperatures of and above. Diamonds are carbon crystals that form deep within the Earth under high temperatures and extreme pressures. At surface air pressure (one atmosphere), diamonds are not as stable as graphite, and so the decay of diamond is thermodynamically favorable (δH = ). So, contrary to De Beers' ad campaign extending from 1948 to at least 2013 under the slogan "A diamond is forever", diamonds are definitely not forever. However, owing to a very large kinetic energy barrier, diamonds are metastable; they will not decay into graphite under normal conditions. See also Chemical vapor deposition of diamond Crystallographic defects in diamond Nitrogen-vacancy center Synthetic diamond References Further reading Pagel-Theisen, Verena. (2001). Diamond grading ABC: The manual (9th ed.), pp. 84–85. Rubin & Son n.v.; Antwerp, Belgium. Webster, Robert, and Jobbins, E. Allan (Ed.). (1998). Gemmologist's compendium, p. 21, 25, 31. St Edmundsbury Press Ltd, Bury St Edwards. External links Properties of diamond Properties of diamond (S. Sque, PhD thesis, 2005, University of Exeter, UK) Diamond Allotropes of carbon Diamond Superhard materials