CALCULATED PHASE-DIAGRAMS FOR ACTIVATED LOW-PRESSURE DIAMOND GROWTH FROM C-H, C-O, AND C-H-O SYSTEMS

Three-dimensional temperature (T)-pressure (P)-composition (X) phase d iagrams of binary carbon-hydrogen (C-H) and carbon-oxygen (C-O) system s for activated low pressure diamond growth have been calculated. Base d on an approximation of linear combination between C-H and C-O system s, a projective ternary carbon-hydrogen-oxygen (C-H-O) phase diagram h as also been obtained. There is always a diamond growth region in each of these phase diagrams. Once a supply of external activating energy stops, the diamond growth region will not exist. Nearly all of the rel iable experimental data reported in the Literature drop into the possi ble diamond growth region of the calculated projective ternary C-H-O p hase diagram under the conditions of 0.01-100 kPa and above 700 K.