Yan Gong, Da Luo, Myeonggi Choe, Yongchul Kim, Babu Ram, Mohammad Zafari, Won Kyung Seong, Pavel Bakharev, Meihui Wang, In Kee Park, Seulyi Lee, Tae Joo Shin, Zonghoon Lee, Geunsik Lee, Rodney S Ruoff
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 °C and at pressures of 5-6 GPa (refs. 1,2 ). Diamond is thermodynamically stable under high-pressure and high-temperature conditions as per the phase diagram of carbon3 . 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 7 GPa and 1,600 °C (refs...
April 24, 2024: Nature