Process for the synthesising diamond single crystals.

摘要

Colorless and transparent, substantially inclusion-free diamond crystals can be synthesized in an economical and stable manner, for use as ornamental articles or in optical parts, by a process for the synthesis of diamond single crystal by a temperature gradient method, which comprises adding at least one element selected from Ti, Zr, Hf, V, Nb or Ta as a nitrogen getter and a material capable of decomposing at least one carbide of Ti, Zr, Hf, V, Nb or Ta to a solvent metal, or a process for the synthesis of diamond single crystal by a temperature gradient method, which comprises adding an alloy or intermetallic compound of the X-Y type (X is selected from Ti, Zr, Hf, V, Nb or Ta and Y is selected from Cu, Ag, Au, Zn or Cd), or a process for the synthesis of diamond single crystal by a temperature gradient method, which comprises adding at least one element selected from Ti, Zr, Hf, V, Nb or Ta as a nitrogen getter and starting the synthesis of diamond under such a state that a metallic plate to prevent formation of carbides on or near the seed surface is arranged between the solvent metal and the seed crystals.