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Lab-grown diamonds of various colors grown by the high-pressure-and-temperature technique. A synthetic diamond or laboratory-grown diamond (LGD), also called a lab-grown diamond, [1] laboratory-created, man-made, artisan-created, artificial, synthetic, or cultured diamond, is a diamond that is produced in a controlled technological process (in contrast to naturally formed diamond, which is ...
The operation of the diamond anvil cell relies on a simple principle: =, where p is the pressure, F the applied force, and A the area. Typical culet sizes for diamond anvils are 100–250 micrometres (μm), such that a very high pressure is achieved by applying a moderate force on a sample with a small area, rather than applying a large force on a large area.
InCent-LGD has three core research groups dedicated to different aspects of lab-grown diamond technology: [5] High Pressure High Temperature (HPHT) Group: This group focuses on the HPHT method of diamond growth, which simulates the natural diamond formation process by subjecting carbon to high pressure and high temperature.
The growth rate for 5 carats (1.0 g) type Ib (yellow, nitrogen-rich) crystals using Fe–Ni catalyst reaches as high as ~20 mg/h towards the end of 100 h growth cycle, i.e. crystals of 5 carats (1.0 g) to 6 carats (1.2 g) can be grown in less than 100 h. [5]
Transition metals nickel and cobalt, which are commonly used for growth of synthetic diamond by high-pressure high-temperature techniques, have been detected in diamond as individual atoms; the maximum concentration is 0.01% for nickel [54] and even less for cobalt. Virtually any element can be introduced to diamond by ion implantation.
The high-pressure synthesis of diamond in 1953 in Sweden [21] [22] and in 1954 in the US, [23] made possible by the development of new apparatus and techniques, became a milestone in synthesis of artificial superhard materials. The synthesis clearly showed the potential of high-pressure applications for industrial purposes and stimulated ...
In absence of oxygen, e.g. in a flow of high-purity argon gas, diamond can be heated up to about 1700 °C. [48] [49] At high pressure (~20 GPa (2,900,000 psi)) diamond can be heated up to 2,500 °C (4,530 °F), [50] and a report published in 2009 suggests that diamond can withstand temperatures of 3,000 °C (5,430 °F) and above. [51]
The higher the cooling capacity, the larger the diamond yield, which can reach 90%. After the synthesis, diamond is extracted from the soot using high-temperature high-pressure boiling in acid for a long period (c. 1–2 days). The boiling removes most of the metal contamination, originating from the chamber materials, and non-diamond carbon.