IIT-M to set up National Centre for lab-grown diamonds

Subject : Science and technology

Section: Msc

Concept :

Finance Minister Nirmala Sitharaman announced in the budget 2023-24, the government’s proposal to focus on lab-grown diamonds by reducing the Customs duty on the seeds used in lab-grown diamond manufacturing.
FM also announced a grant to IITs to facilitate the growth of Lab-Grown Diamonds in India.
This will encourage the indigenous production of LGD seeds, machines and to reduce import dependency.

Lab-Grown Diamonds

Lab-grown diamonds (LGD) are diamonds that are produced in laboratories, using specific technology which mimics the geological processes that grow natural diamonds.

Production Process of LGDs:

LGDs are mostly manufactured through two processes – high pressure, high temperature (HPHT) method or Chemical Vapour Deposition (CVD) method.
High pressure, high temperature (HPHT) method: HPHT method requires extremely heavy presses that can produce up to 730,000 psi of pressure under extremely high temperatures (at least 1500 celsius).
Usually graphite is used as the “diamond seed” and when subjected to these extreme conditions, the relatively inexpensive form of carbon turns into one of the most expensive carbon forms.
Chemical Vapor Deposition (CVD)method: A thin slice of diamond seed is placed in a sealed chamber and heated to around 800 degrees celsius, and then the chamber is filled with other carbon rich gases such as methane.
The gases are ionised into plasma using microwaves, lasers, and other techniques. The ionisation breaks down the gases and allows the carbon to merge with the diamond seed, growing the diamond up layer by layer.
Both HPHT and CVD methods of growing diamonds artificially begin with a seed — a slice of another diamond.

Applications:

LGDs have basic properties similar to natural diamonds, including their optical dispersion, which provide them the signature diamond sheen. However, since they are created in controlled environments, many of their properties can be enhanced for various purposes.
LGDs are most often used for industrial purposes, in machines and tools. Their hardness and extra strength make them ideal for use as cutters.
Pure synthetic diamonds have high thermal conductivity, but negligible electrical conductivity. This combination is invaluable for electronics where such diamonds can be used as a heat spreader for high-power laser diodes, laser arrays and high-power transistors