A Novel Method for 15-Minute Diamond Creation Without Seed Particles
In an effort to boost diamond manufacturing in India, Finance Minister Nirmala Sitharaman announced a reduction in customs duties for ‘seeds’ used in lab-grown diamonds during the 2023-24 budget presentation.
Additionally, a grant of ₹242 crore has been allocated to IIT Madras to establish the India Centre for Lab Grown Diamonds (InCent-LGD), focusing on advanced research in this field.
Traditionally, growing diamonds is a lengthy process.
The conventional ‘high pressure, high temperature’ (HPHT) method, discovered by GE in 1955, typically takes about 12 days to produce synthetic diamonds.
This method involves dissolving carbon in liquid metal under extreme conditions — about 5 Giga Pascals of pressure (50,000 times atmospheric pressure) and temperatures between 1,300–1,600°C.
The carbon atoms migrate towards a diamond seed crystal, gradually forming a diamond lattice over several days.
However, diamonds produced using this technique are generally small.
Seeking a faster and more efficient method for diamond production, a team of Korean scientists has made a groundbreaking discovery.
A Breakthrough in Diamond Production.
In a recent study published in Nature, researchers from the Ulsan National Institute of Science and Technology, including Indian scientist Babu Ram, detailed a method for growing diamonds in just 15 minutes.
This process occurs at a significantly lower temperature of 1,025°C and at ambient pressure, without the need for seed particles.
How It Works
The research team, consisting of 15 scientists, created a unique mixture of gallium, iron, nickel, and silicon placed in a graphite crucible.
By introducing methane at 1,175°C, they observed diamond formation at the bottom of the crucible, where the liquid metal had solidified, resulting in diamonds with a distinctive rainbow coloration.
Using a different form of methane (13CH4), containing an isotope of carbon, they achieved purer diamonds.
The diamond crystals were confirmed through Raman spectroscopy, transmission electron microscopy, and X-ray diffraction.
The team discovered that diamonds nucleate and grow at a central point within the mixture, likely due to a slight temperature gradient.
Carbon atoms rapidly accumulate at this spot, forming diamond structures.
The process begins within 10 to 15 minutes, a stark contrast to the 12-day duration required by the HPHT method.
The diamonds continue to grow but cease to increase in size after approximately 150 minutes.
Significance and Future Potential.
This new method represents a significant advancement in diamond manufacturing.
The ability to produce diamonds at ambient pressure opens up new possibilities for the industry.
While the current method may require further refinement, the researchers believe that modifying the metal mixture could yield even better results.
"The possibilities of exploring diamond growth with this type of approach seem promising," the scientists conclude in their paper.
This innovative technique not only offers a quicker and potentially more scalable way to produce diamonds but also signifies a major step forward in materials science and industrial diamond production.