A method for fabricating nanodiamond particles in a nanodiamond fabrication reactor, which method entails: a) forming a composite of a plurality of diamond monolayers interspersed with a plurality of non-monolayer dihydrobenzvalene (DHB), one over the other, by reacting kinetically energized carbyne radicals with a supported layer of DHB, thus sealing off any subtended, unreacted DHB from further reaction with the kinetically energized carbyne radicals. b) subjecting the diamond monolayers to an anvil having a nanomachined strike face, with sufficient force to fracture the diamond monolayers, to thereby produce nanodiamond having a shape in the X-Y plane matching that of the nanomachined strike face and a Z-axis dimension (thickness) which is that of a diamond monolayer.

A method for fabricating nanodiamond particles in a nanodiamond fabrication reactor, which method entails: a) forming a composite of a plurality of diamond monolayers interspersed with a plurality of non-monolayer dihydrobenzvalene (DHB), one over the other, by reacting kinetically energized carbyne radicals with a supported layer of DHB, thus sealing off any subtended, unreacted DHB from further reaction with the kinetically energized carbyne radicals. b) subjecting the diamond monolayers to an anvil having a nanomachined strike face, with sufficient force to fracture the diamond monolayers, to thereby produce nanodiamond having a shape in the X-Y plane matching that of the nanomachined strike face and a Z-axis dimension (thickness) which is that of a diamond monolayer.

An apparatus to decompose a hydrocarbon reactant into a gaseous product and a solid product includes a reactor volume, a reservoir of liquid material, a plurality of nozzles connected to the reservoir of liquid material, the plurality of nozzles configured to distribute the liquid material into the reactor volume from the reservoir as a liquid mist, a gas inlet connected to a hydrocarbon gas source to receive hydrocarbon gas reactant, a distributor connected to the inlet to distribute the hydrocarbon gas reactant into the reactor volume, a heat source located adjacent the reactor volume configured to heat the reactor volume, a separator to separate the solid product from the liquid material, a re-circulation path connected between the reactor volume and the reservoir to re-circulate the liquid material from the reactor volume to the reservoir, a gas outlet connected to the reactor volume configured to outlet hydrogen gas from the reactor volume, and at least one filter connected to the gas outlet to remove entrained solid product from the hydrogen gas.

A method to decompose a hydrocarbon reactant into a gaseous product and a solid product includes generating a mist of a liquid material within a reactor volume, heating the reactor volume, introducing a hydrocarbon reactant into the reactor volume to produce a solid product and a gaseous product, separating the solid product from the liquid material, removing the solid product and gaseous product from the reactor volume, and recirculating the liquid material be re-introduced to the reactor volume.

A diamond polycrystal includes diamond grains, the diamond polycrystal including a cubic diamond and a 6H type hexagonal diamond, wherein the cubic diamond and the 6H type hexagonal diamond exist in the same or different diamond grains, and a ratio Ab.sub.1/Ab.sub.2 is more than or equal to 0.4 and less than or equal to 1, Ab.sub.1 representing a maximum value of absorption in a range of more than or equal to 1200 cm.sup.−1 and less than or equal to 1300 cm.sup.−1 in an infrared absorption spectrum, Ab.sub.2 representing a maximum value of absorption in a range of more than or equal to 1900 cm.sup.−1 and less than or equal to 2100 cm.sup.−1.

A diamond polycrystal includes diamond grains, the diamond polycrystal including a cubic diamond and a 6H type hexagonal diamond, wherein the cubic diamond and the 6H type hexagonal diamond exist in the same or different diamond grains, and a ratio Ab.sub.1/Ab.sub.2 is more than or equal to 0.4 and less than or equal to 1, Ab.sub.1 representing a maximum value of absorption in a range of more than or equal to 1200 cm.sup.−1 and less than or equal to 1300 cm.sup.−1 in an infrared absorption spectrum, Ab.sub.2 representing a maximum value of absorption in a range of more than or equal to 1900 cm.sup.−1 and less than or equal to 2100 cm.sup.−1.

An ink includes a boron-doped nanodiamond having a specific surface area of 110 m.sup.2/g or greater, and electrical conductivity at 20° C. of 5.0×10.sup.−3 S/cm or greater.

Disclosed herein are synthetic, or cultured diamonds which have at least one artificially embedded inclusion(s) incorporated within their crystal structure during the diamond's deposition or growth process. Disclosed are cultured diamonds having a substrate portion, artificially embedded inclusion(s) disposed on the substrate portion, and an encapsulating portion, formed on the artificially embedded inclusion(s). The substrate portion and the encapsulating portion are bonded together by covalent carbon to carbon bonds.

Disclosed herein are synthetic, or cultured diamonds which have at least one artificially embedded inclusion(s) incorporated within their crystal structure during the diamond's deposition or growth process. Disclosed are cultured diamonds having a substrate portion, artificially embedded inclusion(s) disposed on the substrate portion, and an encapsulating portion, formed on the artificially embedded inclusion(s). The substrate portion and the encapsulating portion are bonded together by covalent carbon to carbon bonds.

An apparatus for fabricating diamond by carbon assembly, which comprises: a) a hydrocarbon radical generator in operable connection with b) a mass flow conduit extending from the hydrocarbon radical generator in a) to an interface and into a primary magnetic accelerator containing one or more electromagnets in operable connection with c) a diamond fabrication reactor comprising a diamond forming deposition substrate. Also disclosed is a method for fabricating diamond by shockwaves using the disclosed apparatus.