Anvils, diamond synthesis

The first artificial diamond synthesis was conducted by the Swedish company ASEA with a six-anvil press in February 1953 (Jackson and Davim 2011). In 1955, General Electric (GE)... 

The contribution of petroleum of abiotic origin to the natural deposits is a topic of enormous importance and actuality. The geologic conditions of the Earth s upper mantle can be easily reproduced by using the diamond anvil cell in combination with different heating methods. The first experimental study of an abiotic hydrocarbons synthesis was performed by Kenney et al. [471]. The... 

Very recently, Solozhenko [540] reported the high-pressure-high-temperature synthesis of cubic BC2N with in situ control of the reaction by x-ray diffraction measurement. The first high-density product has been obtained in a laser-heated diamond anvil cell (DAC). The starting material was g-BC N, prepared... 

Studies at extremely high static pressure can be carried out in diamond anvil cells. Studies of chemical dynamics in gem anvil cells are beginning to be carried out, and some unique chemical synthesis can also occur at these high pressures. For example, a high pressure polymerized phase of carbon monoxide was recently reported to be synthesized using visible laser light to irradiate a carbon monoxide sample at pressures of over 5 GPa in a diamond anvil cell. ... 

High Pressure Synthesis of the Carbon Allotrope Hexagonite with Carbon Nanotubes in a Diamond Anvil Cell... 

The synthesis of a novel 7-813X4 phase with a cubic spinel structure (see Figure 2.1c) was carried out under high pressure (15 G Pa) and at temperatures above 1920 ° C in a laser-heated diamond cell [22]. Today, many different processing techniques for y-813X4 synthesis are available, the most common being the diamond anvil cell (DAC) synthesis (G. 8erghiou, et al., unpublished results), the multianvil pressure apparatus (MAP) synthesis [23], and the shock synthesis [24]. 

The belt apparatus (Fig. 7.3) provides an ideal high pressure-high temperature combination for solid-state synthesis. This apparatus was used for the synthesis of diamonds some years ago. It actually involves a combination of the piston-cylinder and the opposed anvil designs. The apparatus consists of two conical pistons made of tungsten carbide, which ram through a specially shaped chamber from opposite directions. The chamber and pistons are laterally supported by several steel rings,... 

Diamond is not thermodynamically stable at atmospheric pressure, but its transformation into graphite is extremely slow below 800°C. Its synthesis, achieved for the first time in 1955, takes place by treating graphite at 2,700°C, under 12 GPa pressure, in the presence of a catalyst (1% to 2% of B, Be, Si, etc ), in an equipment (anvil, punches) which besides can be made only in sintered hard metal WC-Co. Present global production reaches 400 million carats, which is more than three times the production of natural diamonds (a carat is 1/5 g). 

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