Diamonds Lose Mass in Sunlight

[n2doc]

By James Mitchell Crow of Nature magazine

It might be among the hardest materials known, but place a diamond in a patch of sunlight and it will start to lose atoms, say a team of physicists in Australia. The rate of loss won't significantly trouble tiara wearers or damage diamond rings, but the discovery could prove a boon for researchers working to tap diamond's exceptional optical and electronic properties.

Many of the newest uses of diamonds, from laser light emission to quantum communication and computing, require micro- or nano-features to be built into the surface of the diamond. Physicist Rich Mildren and his team at Macquarie University in Sydney have now shown that beams of ultraviolet (UV) light offer a particularly gentle way to do just that.

Diamonds are usually etched by laser in a process called ablation, which burns atoms from the surface but leaves behind a rough, damaged area more like that of graphite than of diamond. Mildren and his colleagues show that by cutting the pulse power of the laser, a process called desorption takes over, with excited carbon atoms popping off the surface to leave smoothly etched diamond behind.

Mildren and his team discovered the effect by accident while developing diamond-based lasers. "We wanted to show that diamond can operate at wavelengths that other materials cannot, and UV is one such region," says Mildren. The team produced a diamond laser that successfully emitted UV light--but only for about 10 minutes, after which it would always stop working. "It turned out that we were desorbing carbon atoms, making little pits in the diamond surface. It was bad news for laser performance, but good news for this other research direction."

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http://www.scientificamerican.com/article.cfm?id=diamonds-lose-mass-in-sunlight

[MineralMan]

1. You can burn diamonds, too.

As a demonstration for a meeting of mineral collectors, I burned a few grams of diamond abrasive for them. It's one of the few minerals you can set on fire.

Carbon burns.

[PoliticAverse]

2. I guess that's why my house is covered in asbestos shingles not diamond ones... n/t

[MineralMan]

3. Yup. That's why, for sure.

LOL.

[AlecBGreen]

5. cool!

what temp do they need to reach?

[Odin2005]

4. So can we sue DeBeers for claiming that diamonds are forever?

[eppur_se_muova]

6. Diamond dies (for wire drawing) are routinely punched with lasers ...

not sure why this is such big news, but then Iit's NMAOE.

[QED]

7. Lavoisier bured diamonds

in a glass jar in the presence of oxygen to produce carbon dioxide. He got the same result by burning graphite and concluded that graphite and diamonds are both composed of carbon.

Below is Lavoisier's apparatus.

[TalkingDog]

8. Wouldn't want to be an ant in that neighborhood.

Thanks for the pic, that's pretty cool.

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