A diamond prospect - synthetic diamond Global Innovation Centre

The new synthetic diamond Global Innovation Centre (GIC) in Harwell, Oxfordshire, UK, is officially open. Steve Coe, Director of Innovation at GIC operator, Element Six, says that the figure spent on both building the facility and equipment is nearing �30m – though some of this technology is still en route from South Africa.

So what will this 5,000m2 custom-built facility do? Well, it is unique in that it combines chemical vapour deposition (CVD) with high-pressure high-temperature (HPHT) synthetic diamond production to create materials for a range of engineering areas that go beyond mechanical and abrasive applications.

While the hardness properties of synthetic diamond are well known, the applications for it have evolved due to the material’s increasingly low thermal expansion co-efficient, high chemical inertness, high thermal conductivity and wide electronic band gap. Here are a few areas where these innovative synthetic diamond materials are being applied.

Acoustics 

Sound engineering firm Bowers and Wilkins, based in Worthing, UK, has recently partnered with the GIC to use polycrystalline CVD diamond as a component in its loudspeakers. The diamond tweeters break up frequencies of 70kHz.

Environment 

Boron-doped synthetic diamond has unique electrochemical properties that enable efficient oxidisation of organic and inorganic compounds. Ozone technology company Electrolytic Ozone Inc, USA, and the GIC have developed a patented method of generating ozone in water to kill pathogens. The Centre is also developing an O3 disinfectant spray to be used in homes, restaurants and hospitals.

The GIC is also investigating synthetic diamond electrodes to treat industrial wastewaters and landfill leachates that cannot be treated by conventional means.

Road maintenance 

A polycrystalline diamond (PCD) road pick has been developed that combines toughness with wear resistance, achieving more than 40 times the life of standard picks that use tungsten carbide. The use of PCD in this way could help reduce overall milling time, as spot checks are reduced. The pick design will also enhance fuel efficiency, as the PCD retains its shape and so the picks require less penetration force and less energy to function effectively.

Machining and processing 

Polycrystalline cubic boron nitride (PCBN) composites are being used for the production of precision cutting tools for machining ferrous materials such as hard steels, grey and hard-cast irons, and high-temperature superalloys. The high-content PCBN materials can be used for finish machining of cast irons and for extremely abrasive powder metallurgy parts, for example automotive valve seats.

Electronics and semiconductors 

Synthetic diamond has five times the thermal conductivity of copper. CVD diamond heat spreaders could bring a new dimension to thermal management of semiconductor devices and extend device lifetime. The electronic-grade CVD diamond materials are formed of single crystal and polycrystalline plates, and can be used in a variety of demanding radiation detection applications, from medical radiotherapy to neutron detection for radiation level monitoring in civil nuclear and security applications. A joint project with Group4 Labs, USA, has also resulted in a composite semiconductor wafer that comprises a heteroepitaxial gallium nitride compound that offers boosted efficiency for power amplifiers as well as radar and communication satellites.

Another growing field has been synthetic diamond-based quantum applications. The use of electronic-grade single crystal CVD with extremely low levels of impurities (<0.05ppb) combined with very high levels of nitrogen dopants (>100ppm) could open up a range of further applications in quantum computing. Another advantage is that the quantum properties hosted in a synthetic diamond can be manipulated and probed at room temperature.

http://www.iom3.org/news/diamond-prospect-synthetic-diamond-global-innovation-centre