Innovations in synthetic diamond making add some glitter to life
EVER since the first synthetic diamond
process - the high-pressure catalytic
- was perfected by General Electric i
and De Beers in South Africa, the mat
found many applications in industry.
The remarkable mechanical prop diamond make it ideal for many pt Synthetic diamonds are extensively grinding and cutting tools and in m turing wear-resistant surfaces and evi speaker diaphragms. In the late 1(ft approach called the chemical vapour tion method was developed. This rn chief drawback is that the growth r exceedingly slow. For a good quality d deposit, the best growth rate at optin ditions is roughly one micrometre p This shortcoming has affected the eco use of diamonds. A recent study by P G Partridge, Internal of Medical Science, has rised id an increase in the growth rates of D& by the chemical vapour deposi i6chmique. The technique involves @p a plasma by microwaves and a awbon charge in hydrogen gas, and pmg the diamond on a substrate a usuafly tungsten (Nature, Vol 377, 21, 1995).
r11w insight provided by Partridge coHeagues has led to the discovery Ki2l deposition on many closely ints, if allowed to grow (side-can increase the effective growth ifold. They have used a small rr tungsten spiral upon which the diamond is deposited. The effective growth rate is increased by the number of turns of the spiral. They have also done detailed calculations to show that a closely spaced grid can be coated simultaneously with a continuous, though not very smooth, sheet of diamond.
The increased growth rates for diamond deposition could bring down the costs substantially and make it economical for various other applications. These include diamond-reinforced, high strength composites for high technology uses. The coming years will defenitely mean large- scale incorporation of chemically deposited diamonds for diverse applications.
We are a voice to you; you have been a support to us. Together we build journalism that is independent, credible and fearless. You can further help us by making a donation. This will mean a lot for our ability to bring you news, perspectives and analysis from the ground so that we can make change together.
Comments are moderated and will be published only after the site moderator’s approval. Please use a genuine email ID and provide your name. Selected comments may also be used in the ‘Letters’ section of the Down To Earth print edition.