Concerning the Transition of Diamond into the Metallic State
Vereshchagin L.F., Yakovlev E.H. , Vinogradov B.V. , Sakun V.P., Stepanov G.N .
It is shown experimentally that at pressures on the order of 1 megabar, in the temperature interval from 77 to 600°K, üô/üò is negative on the equilibrium curve of the dielectric and metallic phases of diamond.