Patent ID: 11905620
Assignee: QUFU NORMAL UNIVERSITY
Field: Surface technology, coating (Chemistry)
Classification: CPC C  G | IPC C  G

Claim 0:
1. A method for preparing a diamond anvil, comprising the following steps:
(1) using an iron-nickel catalyst system, taking a high-purity graphite as a carbon source, taking Al/Ti as a nitrogen remover, and taking a <100> diamond as a crystal seed, synthesizing a single crystal diamond by keeping a temperature of 1460° C. for 60 h at a pressure of 5.5 GPa; wherein a nitrogen content of a <100> crystal orientation growth region of the single crystal diamond is in a range of 20-80 ppm, and a nitrogen content of a <111> crystal orientation growth region of the single crystal diamond is in a range of 200-300 ppm;
(2) performing a high-pressure-high-temperature (HPHT) annealing on the single crystal diamond at an annealing pressure of 5 GPa for 4 h at temperatures of 1400° C., 1500° C., 1600° C. and 1700° C., respectively; and
(3) performing cutting on the diamond anvil by placing an anvil surface of the diamond anvil inside a <311> crystal orientation growth region, and placing a main body of the diamond anvil in the <111> crystal orientation growth region; wherein a thickness of the anvil surface is 15 μm, and a depth of the nitrogen vacancies in the obtained diamond anvil is 15 μm.