Carbon atoms set free by UV light

Nature : A team of physicists in Australia has found that sunlight can cause diamond to lose atoms. Diamonds are usually etched by laser in a process called ablation, whereby atoms are burned from the surface, leaving behind a rough, damaged area more like that of graphite, writes James Mitchell Crow for Nature. Rich Mildren and his team at Macquarie University in Sydney have shown that by cutting the laser’s pulse power, a process called desorption takes over, with excited carbon atoms popping off the surface to leave smoothly etched diamond. However, the rate of loss is very slow—even a typical mercury UV lamp in a lab would take about 10 billion years to remove a microgram of diamond. How the desorption process works is still to be determined, but Mildren has published several theories in Optical Materials Express. The discovery could prove a boon for researchers working to tap diamond’s exceptional optical and electronic properties.