Diamond has many anticipated superiorities for various technological applications and therefore the diamond growth has been a forefront of material research in recent decades. There has been some progress in areas such as the rate of growth and the physical size of the polycrystals. These crystals can be oriented from each other. However, they are disjointed macroscopically or joined with multiple grain boundaries and a realization of a large single crystal diamond does not seem to be in sight. The present invention represents a drastically different synthesis approach by growing of diamond on liquids surface. The current prevailing practice of growing diamond is on solid substrate. A hindrance to grow a large area, single crystal diamond for many technological applications is a low mobility of the carbon species on the surface of a solid substrate. Another deficiency of a solid surface is the structural imperfection, such as the dislocation and the grain boundary, which could induce a prolific and random growth of diamond crystallites. Furthermore, these crystallites on the solid surface are immobile, and once after they are formed, they cannot organize among the neighbors to form jointly a single crystal.
A growth of diamond on a solid substrate is referred to as a solid epitaxy or simply, epitaxy. When the substrate during the crystal growth is a liquid, which is the case in the present invention, the process will be a rheotaxy. In rheotaxy, the substrate surface will have a perfect smoothness and no structural defects, such as the grain boundaries. A conceptual advantage of the liquid surface to grow diamond is the high mobility on two levels:
(1) On the atomic level, a carbon atom has a higher mobility on a liquid surface than on a solid surface. This mobility would facilitate an aggregation of the carbon atoms to form diamond crystallites, and PA1 (2) On the macroscopic level, diamond crystallites adhere comparatively weakly to the surface of liquid than a solid.
A combination of (1) and (2) produces the following benefits: In the liquid, due to a lower specific gravity of diamond than that of liquid to be adapted in the present invention, the diamond crystallites would float on the liquid. These floating islets could be mobile and could coalesce due to several mechanisms such as electric field, thermal fluctuations, gas turbulence from the carbon impact, and mechanical vibration from surroundings. With a manipulation of these sources, the crystallites could be aligned crystallographically and morphologically from each other to form a large single crystal. This will be the basis of the present invention.
USPTO Backgrounds
USPTO Backgrounds