Growth of diamond in liquid metal at 1 atm pressure

• 成果类型: Article
• 署名作者: Gong, Yan; Luo, Da; Choe, Myeonggi; Kim, Yongchul; Ram, Babu; Zafari, Mohammad; Seong, Won Kyung; Bakharev, Pavel; Wang, Meihui; Park, In Kee; Lee, Seulyi; Shin, Tae Joo; Lee, Zonghoon; Lee, Geunsik; Ruoff, Rodney S.
• 署名单位: Institute for Basic Science - Korea (IBS); Ulsan National Institute of Science & Technology (UNIST); Ulsan National Institute of Science & Technology (UNIST); Ulsan National Institute of Science & Technology (UNIST); Ulsan National Institute of Science & Technology (UNIST); Ulsan National Institute of Science & Technology (UNIST); Huazhong University of Science & Technology
• 刊物名称: Nature
• ISSN/ISSBN: 0028-4292
• DOI: 10.1038/s41586-024-07339-7
• 发表日期: 2024-05-09
• 页码: 348-+
• 关键词: generalized gradient approximation; chemical-vapor-deposition; single-crystal; cvd-diamond; graphite; carbon; DYNAMICS; state; phase

摘要

Natural diamonds were (and are) formed (thousands of million years ago) in the upper mantle of Earth in metallic melts at temperatures of 900-1,400 degrees C and at pressures of 5-6GPa (refs.(1,2)). Diamond is thermodynamically stable under high-pressure and high-temperature conditions as per the phase diagram of carbon(3). Scientists at General Electric invented and used a high-pressure and high-temperature apparatus in 1955 to synthesize diamonds by using molten iron sulfide at about 7GPa and 1,600 degrees C (refs.(4-6)). There is an existing model that diamond can be grown using liquid metals only at both high pressure and high temperature(7). Here we describe the growth of diamond crystals and polycrystalline diamond films with no seed particles using liquid metal but at 1atm pressure and at 1,025 degrees C, breaking this pattern. Diamond grew in the subsurface of liquid metal composed of gallium, iron, nickel and silicon, by catalytic activation of methane and diffusion of carbon atoms into and within the subsurface regions. We found that the supersaturation of carbon in the liquid metal subsurface leads to the nucleation and growth of diamonds, with Si playing an important part in stabilizing tetravalently bonded carbon clusters that play a part in nucleation. Growth of (metastable) diamond in liquid metal at moderate temperature and 1atm pressure opens many possibilities for further basic science studies and for the scaling of this type of growth.