Dr. SEONG Won Kyung from the Center for Multidimensional Carbon Materials

Often seen as a symbol of eternal love due to its enduring nature, diamond, the “king of gems”, is composed of carbon and is also considered the ultimate semiconductor material due to its exceptional strength and high thermal conductivity. However, using natural diamonds is prohibitively expensive, and creating lab-grown diamonds is incredibly challenging. These synthetic diamonds require extremely high pressures, 50,000 to 60,000 times standard atmospheric pressure, and temperatures of over a thousand degrees, making the process complex and limiting the size of diamonds that can be produced.

The Institute for Basic Science (IBS) Center for Multidimensional Carbon Materials has overcome these limitations with a new breakthrough. They have successfully synthesized diamonds using liquid metal alloys at standard atmospheric pressure. Additionally, through spectroscopic analysis, they discovered a "silicon-vacancy color center" structure within the diamonds. This structure, where silicon atoms are embedded within the diamond crystal, exhibits quantum properties and high magnetic sensitivity. This research was published in the journal "Nature" in April and is expected to impact the development of related industries in Korea.

Researcher SEONG Won Kyung, a key participant in this study, compared researching carbon materials like diamonds is similar to getting to know a new friend. While carbon is a familiar material present in many substances around us and even in our bodies, it has an incredibly diverse range of properties.
Seong emphasized the importance of humility in research, stating that even after a single success, it is crucial to avoid complacency and remain objective. We asked Seong about his research life and accomplishments.

Please introduce yourself.

Hello. I am SEONG Won Kyung, a researcher at the Institute for Basic Science (IBS) Center for Multidimensional Carbon Materials, and the team leader of the Thin Films and Properties Analysis Team. I completed my doctoral studies at Sungkyunkwan University, focusing on the growth mechanism and properties analysis of superconducting thin films. I then worked as a postdoctoral researcher at the Korea Institute of Science and Technology (KIST) and later at Quantum Design Korea, before joining the current research group in February 2017.

Please introduce the Center for Multidimensional Carbon Materials.

Our Center studies various allotropes of carbon. Representative carbon allotropes include two-dimensional materials like graphene and three-dimensional materials like graphite and diamond.

The group consists of the materials group, the nano-optics group, the synthesis group, and the analysis group. The materials group, to which I belong, focuses on the growth and chemical or physical property control of single-crystal two-dimensional materials like graphene and graphite, as well as other carbon allotropes such as diamond. The nano-optics group studies the microscopic world of carbon allotropes using nano-sized light. The synthesis group explores new polymer synthesis methods, while the analysis group uses electron microscopy to study the microscopic crystal structures, elemental analysis, and real-time growth mechanisms of carbon allotropes.

What is the focus of your research? We are also curious about what made you enter research.

My team and I primarily grow single-crystal carbon allotropes like graphene and graphite and analyze their mechanical and structural properties. We also explore novel methods to synthesize diamonds and study carbon isotope separation techniques.

Understanding the physical properties of any material requires creating "defect-free materials." Defect-free materials exhibit clear changes in their inherent properties when controlled. Synthesizing such materials, especially diamonds, is particularly difficult and complex.

Researching these materials feels like getting to know a new friend more deeply over time. Carbon materials are familiar yet mysterious, with various properties depending on their structural arrangements. My fascination with carbon materials, both common and extraordinary, led me to this research. The continual discovery of new properties in carbon materials is incredibly rewarding.

We would like to know some recent research outputs. What effects did they have in the field?

We published a paper in "Nature" about synthesizing diamonds using liquid metal at standard atmospheric pressure. This idea stemmed from a 2017 "Science" article discussing hydrogen separation from methane gas using liquid gallium. We theorized that the carbon separated from methane using liquid metal could be used to create diamonds.

Typically, diamonds are synthesized using high-temperature and high-pressure methods, requiring intricate equipment to achieve 1,600 degrees Celsius and 50,000 times atmospheric pressure. This limits the size of synthetic diamonds to about 1 cm³. Our research presents a method to overcome these limitations.

Additionally, we reported in "Small" how the shape of initial carbon precursors affects the graphitization process. Although much research has been conducted on carbon fibers, the impact of precursor shapes on graphitization has not been studied. Our research analyzed the influence of the geometric structure of polymer precursors on the crystallinity of synthesized graphite, considering chemical composition and molecular arrangement changes during heat treatment. This study suggests that controlling the shape of initial precursors allows for the synthesis of carbon composite materials with both high strength and flexibility, such as carbon fibers.

What are some difficulties you faced during the experiment?

Conducting experiments teaches the importance of humility. Instead of celebrating a single success, we focus on reproducibility and meticulous data analysis, striving to remain objective and cautious even with positive results.

What are some challenges you faced during your path as a researcher?

The biggest challenge in research is communication and understanding among team members. I strive to build rapport with my team through frequent conversations, sharing concerns, and making collaborative decisions. Discussing problems openly and brainstorming solutions fosters a sense of unity and shared purpose.

Please tell us your future research plans.

Our team will continue to study the mechanical properties of large-area single-crystal graphene, develop new synthesis methods to overcome the limitations of existing single-crystal graphene, and research easy techniques for carbon isotope separation.

What support would you need for future research?

While excellent research institutions exist abroad, Korea also has many outstanding research facilities and rapid advancements in research outcomes. Korean researchers are diligent and smart, and I hope they continue to work in Korea. Therefore, creating an environment that supports Korean researchers' work is crucial.

Please tell us your final thoughts.

Through my academic and postdoctoral experiences and my time at IBS, I have gained valuable insights and conducted extensive collaborative research. I believe new researchers joining our group will have similar opportunities. I look forward to continued support and interest in the Center for Multidimensional Carbon Materials to sustain excellent research.