An isotopical pure diamond is a type of

diamond Diamond is a Allotropes of carbon, solid form of the element carbon with its atoms arranged in a crystal structure called diamond cubic. Diamond is tasteless, odourless, strong, brittle solid, colourless in pure form, a poor conductor of e ...

that is composed entirely of one

isotope Isotopes are distinct nuclear species (or ''nuclides'') of the same chemical element. They have the same atomic number (number of protons in their Atomic nucleus, nuclei) and position in the periodic table (and hence belong to the same chemica ...

carbon Carbon () is a chemical element; it has chemical symbol, symbol C and atomic number 6. It is nonmetallic and tetravalence, tetravalent—meaning that its atoms are able to form up to four covalent bonds due to its valence shell exhibiting 4 ...

. Isotopically pure diamonds have been

manufactured Manufacturing is the creation or production of goods with the help of equipment, labor, machines, tools, and chemical or biological processing or formulation. It is the essence of the secondary sector of the economy. The term may refer to a ...

from either the more common carbon isotope with

mass number The mass number (symbol ''A'', from the German word: ''Atomgewicht'', "atomic weight"), also called atomic mass number or nucleon number, is the total number of protons and neutrons (together known as nucleons) in an atomic nucleus. It is appro ...

12 (abbreviated as ¹²C) or the less common ¹³C isotope. Compared to natural diamonds that are composed of a mixture of ¹²C and ¹³C isotopes, isotopically pure diamonds possess improved characteristics such as increased

thermal conductivity The thermal conductivity of a material is a measure of its ability to heat conduction, conduct heat. It is commonly denoted by k, \lambda, or \kappa and is measured in W·m−1·K−1. Heat transfer occurs at a lower rate in materials of low ...

. Thermal conductivity of diamonds is at a minimum when ¹²C and ¹³C are in a ratio of 1:1 and reaches a maximum when the composition is 100% ¹²C or 100% ¹³C.

Manufacture

The isotopes of carbon can be separated in the form of

carbon dioxide Carbon dioxide is a chemical compound with the chemical formula . It is made up of molecules that each have one carbon atom covalent bond, covalently double bonded to two oxygen atoms. It is found in a gas state at room temperature and at norma ...

gas by cascaded chemical exchange reactions with amine carbamate. Such CO₂ can be converted to methane and from there to isotopically pure

synthetic diamond A synthetic diamond or laboratory-grown diamond (LGD), also called a lab-grown, laboratory-created, man-made, artisan-created, artificial, or cultured diamond, is a diamond that is produced in a controlled technological process, in contrast to ...

s. Isotopically enriched diamonds have been synthesized by application of

chemical vapor deposition Chemical vapor deposition (CVD) is a vacuum deposition method used to produce high-quality, and high-performance, solid materials. The process is often used in the semiconductor industry to produce thin films. In typical CVD, the wafer (electro ...

followed by

high pressure In science and engineering the study of high pressure examines its effects on materials and the design and construction of devices, such as a diamond anvil cell, which can create high pressure. ''High pressure'' usually means pressures of thousan ...

Types

Carbon 12

The ¹²C isotopically pure, (or in practice 15-fold enrichment of isotopic number, 12 over 13 for carbon) diamond gives a 50% higher

than the already high value of 900-2000 W/(m· K) for a normal diamond, which contains the natural isotopic mixture of 98.9% ¹²C and 1.1% ¹³C. This is useful for heat sinks for the

semiconductor A semiconductor is a material with electrical conductivity between that of a conductor and an insulator. Its conductivity can be modified by adding impurities (" doping") to its crystal structure. When two regions with different doping level ...

industry.

Carbon 13

Isotopically pure ¹³C diamond layers 20 micrometers thick are used as stress sensors due to the advantageous

Raman spectroscopy Raman spectroscopy () (named after physicist C. V. Raman) is a Spectroscopy, spectroscopic technique typically used to determine vibrational modes of molecules, although rotational and other low-frequency modes of systems may also be observed. Ra ...

properties of ¹³C.

References

{{reflist Synthetic diamond Isotopes of carbon