GOALI: Manufacturing Large, Diamond Single Crystals via High-Pressure, High-Temperature Growth

This Grant Opportunities for Academic Liaison with Industry (GOALI) award supports research that contributes new knowledge related to diamond single crystal manufacturing, promoting science and advancing national prosperity, health, and security. Diamond single crystals have long been prized as gemstones but have also shown great promise for new technical applications because of their unique properties. While natural diamonds are formed from carbon in the earth’s crust at depths greater than 100 miles, these conditions can be mimicked in the laboratory allowing synthetic diamond crystals of the highest quality to be manufactured using the High-Pressure, High-Temperature growth process. This grant supports fundamental research to improve this process so that single-crystal diamonds can be manufactured in larger sizes, at ultra-high quality, and for less cost, thus enabling application in optical elements for high-power X-ray systems, as well as in devices for radiation detectors in nuclear reactors and medical applications, power electronics, and quantum computing. Results from this research will favorably impact economic competitiveness, and national security. This research involves several disciplines including advanced manufacturing, computational modeling, crystal growth, and materials science. The multi-disciplinary approach helps broaden participation and positively impacts engineering education.Manufacturing processes employed to grow large, single crystals must achieve atomic-level structural perfection while simultaneously maintaining yields that are high enough to meet cost objectives. This project addresses the production of single-crystal diamond via crystal growth in a High-Pressure, High-Temperature system. This system has the capability to grow diamonds of the highest crystalline quality. However, extreme pressure (5 GPa) and temperature (1,500 K) make direct, in situ diagnostics of growth impossible and modeling a vital tool for process improvement. This project develops and applies novel computational models based on thermodynamics, kinetics, and transport to better understand the fundamental mechanisms responsible for single-crystal diamond growth in the High-Pressure, High-Temperature system. These models are validated via growth experiments conducted by GOALI partner, Euclid Beamlabs, LLC, and applied to improve manufacturing outcomes, such as large crystal size and increased growth rate. An important goal is to avoid process conditions leading to inclusions, which are micron-sized defects containing metallic solvent trapped during growth. Multi-scale models describe steps of atomic height that move across the facets of the growing diamond and predict when an equidistant train of steps destabilizes to form bunches, triggering inclusion formation. Understanding the onset of bunching thus allows innovative growth strategies, such as time-dependent tilting of the system, to be assessed by modeling and tested using experiments.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.