Diamonds, the hardest known naturally occurring material, are a good conductor of heat but cannot conduct an electrical charge. Now, a collaboration of researchers from institutes such as the Zhengzhou University, Henan Academy of Sciences, Ningbo University, and Jilin University have successfully developed diamonds that are capable of conducting electricity, the South China Morning Post (SCMP) reported.
Most naturally formed diamonds are at least a billion years old and have slowly formed at depths of up to 155 miles (250 km) under the surface of the Earth. Known for their hardness and thermal conductivity, the highest among naturally occurring materials, diamonds have also found applications in day-to-day applications.
The high price of diamonds has also spawned an industry of synthetically created ones where high-purity carbon is treated under extreme conditions to generate laboratory-grown diamonds. Zhengzhou in Henan, China, is the world’s largest producer of lab-grown diamonds and contributes to 80 percent of China’s exports of synthetic diamonds. Working with scientists, the industry has learned how to make diamonds that can conduct electricity.
How are conducting diamonds made?
Techniques such as high pressure and high temperature (HPHT) or carbon vapor deposition (CVD) are used to make synthetic diamonds. However, these will still retain the properties of the naturally occurring diamond, which does not conduct electricity.
The researchers used graphene, another form of carbon with high electrical conductivity, to develop conducting diamonds. The method used by the researchers involves the formation of centimeter-sized composites of diamond and graphene.
Using nanodiamonds, the researchers synthesized ultrafine diamond grains interconnected with graphene layers. The process was carried out under a moderate temperature range of 2,372-2,732 degrees Fahrenheit (1,300 and 1,500 degrees Celsius) and pressure conditions of 12 gigapascals.
These conditions are compatible with existing methods for creating lab-grown diamonds, experts in diamond materials and high-pressure physics research told the SCMP.
Where will the conducting diamonds be used?
The composite structure of these new diamonds also retains the toughness of diamonds, meaning it won’t be easy to rupture them. The researchers suggest this makes them ideal for use in demanding environments such as air and spacecraft engines.
Since the material is also durable, it could be deployed in the electrocatalysis step of sewage treatment. Alternatively, highly acidic or alkaline environments that are extremely hot to operate in could allow the new diamond to show its prowess.
Since researchers have used graphene, the new diamonds look a blunt black instead of the polishing clear or tinted colors one expects diamonds to be in. The diamonds produced in the experimental stage were half an inch (13 mm) in diameter and no more than two millimeters thick. One could assume them to be a soiled coin at first glance.
The researchers are, however, confident that without growing application demands, they will be able to modify the size and shape of the diamond produced. “Our findings pave the way for realizing conductive and super hard large-sized diamond materials under mild synthetic conditions, facilitating their practical utilization in related industrial applications,” the researchers wrote in a paper they published in February.
Source: IE
