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Silicon carbide (SiC), also known as carborundum (/ ˌ k ɑːr b ə ˈ r ʌ n d əm /), is a hard chemical compound containing silicon and carbon. A wide bandgap semiconductor , it occurs in nature as the extremely rare mineral moissanite , but has been mass-produced as a powder and crystal since 1893 for use as an abrasive .
The 2H-SiC structure is equivalent to that of wurtzite and is composed of only elements A and B stacked as ABABAB. The 4H-SiC unit cell is two times longer, and the second half is twisted compared to 2H-SiC, resulting in ABCB stacking. The 6H-SiC cell is three times longer than that of 2H, and the stacking sequence is ABCACB.
SiC–SiC composites have a relatively high thermal conductivity and can operate at very high temperatures due to their inherently high creep and oxidation resistance. Residual porosity and stoichiometry of the material can vary its thermal conductivity, with increasing porosity leading to lower thermal conductivity and presence of Si–O–C ...
The Acheson process is a method of synthesizing silicon carbide (SiC) and graphite invented by Edward Goodrich Acheson and patented by him in 1896. Process
It has the chemical formula SiC and is a rare mineral, discovered by the French chemist Henri Moissan in 1893. Silicon carbide or moissanite is useful for commercial and industrial applications due to its hardness , optical properties and thermal conductivity .
There are several manufacturing approaches to making silicon carbide fibers. [5] [6] The one with the longest historical experience, invented in 1975 and called the Yajima process, [7] uses a pre-ceramic liquid polymer that is injected through a spinneret to produce solidified green (unfired) fibers that go through a series of processing steps, including significant time in high temperature ...
A fatal virus has been discovered in shrews in Alabama, sparking concerns about potential contagion to humans. The Camp Hill virus was discovered by researchers at The University of Queensland.
A compound semiconductor is a semiconductor compound composed of chemical elements of at least two different species. These semiconductors form for example in periodic table groups 13–15 (old groups III–V), for example of elements from the Boron group (old group III, boron, aluminium, gallium, indium) and from group 15 (old group V, nitrogen, phosphorus, arsenic, antimony, bismuth).