钻石
材料科学
拉曼光谱
金刚石材料性能
碳纤维
分析化学(期刊)
菱形
石墨
金刚石顶砧
甲烷
化学工程
矿物学
冶金
化学
复合材料
衍射
光学
物理
有机化学
色谱法
复合数
工程类
作者
Yan Gong,Da Luo,Myeonggi Choe,Won Kyung Seong,Pavel V. Bakharev,Meihui Wang,Seulyi Lee,Tae Joo Shin,Zonghoon Lee,Rodney S. Ruoff
出处
期刊:Research Square - Research Square
日期:2023-07-05
被引量:1
标识
DOI:10.21203/rs.3.rs-3130239/v1
摘要
Abstract Natural diamonds were (and are) formed (some, billions of years ago) in the Earth’s upper mantle in metallic melts in a temperature range of 900–1400°C and at pressures of 5–6 GPa 1,2 ; indeed, diamond is thermodynamically stable under high pressure and high temperature (HPHT) conditions as per the phase diagram of carbon 3 . Scientists at General Electric invented and used a HPHT apparatus in 1955 to synthesize diamonds from melted iron sulfide at about 7 GPa and 1600°C 4–6 . There is an existing paradigm that diamond can be grown using liquid metals only at both high pressure (typically 5–6 GPa) and high temperature (typically 1300–1600°C) where it is the stable form of carbon 7 . Here, we describe the growth of diamond crystals and polycrystalline diamond films with no seed particles using liquid metal but at 1 atmosphere pressure, and at 1025°C, breaking this paradigm. Diamond grew at the interface of liquid metal composed of gallium, iron, nickel, and silicon and a graphite crucible , by catalytic activation of methane and diffusion of carbon atoms in the subsurface region of the liquid metal. Raman spectroscopy with 13 C-labeling proves that methane introduced into the growth chamber is the carbon source for many of the regions of newly grown diamond. The new growth diamonds were studied by Raman spectroscopy, scanning and transmission electron microscopy, X-ray diffraction, and photoluminescence. Growth of (metastable) diamond in liquid metal at moderate temperature and 1 atm pressure opens many possibilities for further basic science studies and for the scaling of this type of growth.
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