Amorphous carbonia
Encyclopedia
Amorphous carbonia, also called a-carbonia or a-CO2, is an exotic amorphous solid form of carbon dioxide
that is analogous to amorphous silica glass. It was first made in the laboratory in 2006 by subjecting dry ice
to high pressures (40-48 gigapascal, or 400,000 to 480,000 atmosphere
s), in a diamond anvil. Amorphous carbonia is not stable at ordinary pressures -- it quickly reverts to normal CO2.
While normally carbon dioxide forms molecular crystals, where individual molecules are bound by Van der Waals force
s, in amorphous carbonia a covalently bound
three-dimensional network of atoms is formed, in a structure analogous to silicon dioxide
or germanium dioxide
glass
.
Mixtures of a-carbonia and a-silica may be a prospective very hard and stiff glass material stable at room temperature. Such glass may serve as protective coatings, e.g. in microelectronics
.
The discovery has implications for astrophysics
, as interiors of massive planets
may contain amorphous solid carbon dioxide.
Carbon dioxide
Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...
that is analogous to amorphous silica glass. It was first made in the laboratory in 2006 by subjecting dry ice
Dry ice
Dry ice, sometimes referred to as "Cardice" or as "card ice" , is the solid form of carbon dioxide. It is used primarily as a cooling agent. Its advantages include lower temperature than that of water ice and not leaving any residue...
to high pressures (40-48 gigapascal, or 400,000 to 480,000 atmosphere
Atmosphere
An atmosphere is a layer of gases that may surround a material body of sufficient mass, and that is held in place by the gravity of the body. An atmosphere may be retained for a longer duration, if the gravity is high and the atmosphere's temperature is low...
s), in a diamond anvil. Amorphous carbonia is not stable at ordinary pressures -- it quickly reverts to normal CO2.
While normally carbon dioxide forms molecular crystals, where individual molecules are bound by Van der Waals force
Van der Waals force
In physical chemistry, the van der Waals force , named after Dutch scientist Johannes Diderik van der Waals, is the sum of the attractive or repulsive forces between molecules other than those due to covalent bonds or to the electrostatic interaction of ions with one another or with neutral...
s, in amorphous carbonia a covalently bound
Covalent bond
A covalent bond is a form of chemical bonding that is characterized by the sharing of pairs of electrons between atoms. The stable balance of attractive and repulsive forces between atoms when they share electrons is known as covalent bonding....
three-dimensional network of atoms is formed, in a structure analogous to silicon dioxide
Silicon dioxide
The chemical compound silicon dioxide, also known as silica , is an oxide of silicon with the chemical formula '. It has been known for its hardness since antiquity...
or germanium dioxide
Germanium dioxide
Germanium dioxide, also called germanium oxide and germania, is an inorganic compound, an oxide of germanium. Its chemical formula is GeO2. Other names include germanic acid, G-15, and ACC10380...
glass
Glass
Glass is an amorphous solid material. Glasses are typically brittle and optically transparent.The most familiar type of glass, used for centuries in windows and drinking vessels, is soda-lime glass, composed of about 75% silica plus Na2O, CaO, and several minor additives...
.
Mixtures of a-carbonia and a-silica may be a prospective very hard and stiff glass material stable at room temperature. Such glass may serve as protective coatings, e.g. in microelectronics
Microelectronics
Microelectronics is a subfield of electronics. As the name suggests, microelectronics relates to the study and manufacture of very small electronic components. Usually, but not always, this means micrometre-scale or smaller,. These devices are made from semiconductors...
.
The discovery has implications for astrophysics
Astrophysics
Astrophysics is the branch of astronomy that deals with the physics of the universe, including the physical properties of celestial objects, as well as their interactions and behavior...
, as interiors of massive planets
Gas giant
A gas giant is a large planet that is not primarily composed of rock or other solid matter. There are four gas giants in the Solar System: Jupiter, Saturn, Uranus, and Neptune...
may contain amorphous solid carbon dioxide.