Material with small overlap between conduction and valence bands
Not to be confused with Half-metal.
For the class of chemical elements on the periodic table, see metalloid.
Filling of the electronic states in various types of materials at equilibrium. Here, height is energy while width is the density of available states for a certain energy in the material listed. The shade follows the Fermi–Dirac distribution (black: all states filled, white: no state filled). In metals and semimetals the Fermi level EF lies inside at least one band. In insulators and semiconductors the Fermi level is inside a band gap; however, in semiconductors the bands are near enough to the Fermi level to be thermally populated with electrons or holes. "intrin." indicates intrinsic semiconductors.
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A semimetal is a material with a very small overlap between the bottom of the conduction band and the top of the valence band.
According to electronic band theory, solids can be classified as insulators, semiconductors, semimetals, or metals. In insulators and semiconductors the filled valence band is separated from an empty conduction band by a band gap. For insulators, the magnitude of the band gap is larger (e.g., > 4 eV) than that of a semiconductor (e.g., < 4 eV). Because of the slight overlap between the conduction and valence bands, semimetals have no band gap and a negligible density of states at the Fermi level. A metal, by contrast, has an appreciable density of states at the Fermi level because the conduction band is partially filled.[1]
^Burns, Gerald (1985). Solid State Physics. Academic Press, Inc. pp. 339–40. ISBN 978-0-12-146070-9.
A semimetal is a material with a very small overlap between the bottom of the conduction band and the top of the valence band. According to electronic...
Weyl semimetals are semimetals or metals whose quasiparticle excitation is the Weyl fermion, a particle that played a crucial role in quantum field theory...
holes. The two conical surfaces touch each other and form a zero-band gap semimetal. The name of Dirac cone comes from the Dirac equation that can describe...
1940–1960. Metalloids are sometimes called semimetals, a practice that has been discouraged, as the term semimetal has a different meaning in physics than...
electrons from the valence to the conduction band. Hence, in the case of a semimetal with an overlap region, the electrical conductivity is high. If there...
In July 2015, Weyl fermions have been experimentally realized in Weyl semimetals. Composite particles (such as hadrons, nuclei, and atoms) can be bosons...
consistent in the overall pattern, like a solid. Topological semimetals: Weyl semimetal Dirac semimetal Topological superconductor Metallic and insulating states...
new state, a correlation-driven Weyl semimetal. The team dubbed this new quantum material Weyl-Kondo semimetal. Hewson, Alex C; Jun Kondo (2009). "Kondo...
properties characteristic of both. They are often termed semimetals or metalloids. The term "semimetal" used in this sense should not be confused with its...
Alidoust; Madhab Neupane; et al. (16 July 2015). "Discovery of a Weyl fermion semimetal and topological Fermi arcs". Science. 349 (6248). AAAS: 613–617. arXiv:1502...
Cadmium arsenide (Cd3As2) is an inorganic semimetal in the II-V family. It exhibits the Nernst effect. Cd3As2 dissociates between 220 and 280 °C according...
examples of Dirac matter are graphene and other Dirac semimetals, topological insulators, Weyl semimetals, various high-temperature superconductors with d...
distribution (black: all states filled, white: no state filled). In metals and semimetals the Fermi level EF lies inside at least one band. In insulators and semiconductors...
including steel (which contains cementite, Fe3C), as well as other metal and semimetal carbides (including "ionic" carbides, e.g, Al4C3 and CaC2 and "covalent"...
The sulfide minerals are chemical compounds of one or more metals or semimetals with a chalcogen or pnictogen, of which sulfur is most common. Tellurium...
"compelling evidence" for observed excitons condensing in the three-dimensional semimetal 1T-TiSe2. Normally, excitons in a semiconductor have a very short lifetime...
Mn3Sn, paramagnet CoSn, ferrimagnet TbMn6Sn6, hard ferromagnet (and Weyl semimetal) Co3Sn2S2, and soft ferromagnet Fe3Sn2. Until 2019, all known kagome materials...
close packing leads to a high density of 5.73 g/cm3. Grey arsenic is a semimetal, but becomes a semiconductor with a bandgap of 1.2–1.4 eV if amorphized...
electronegativity is decreased, the bonding may then lead to a semiconductor, a semimetal or eventually a metallic conductor with metallic bonding. Coulomb's law...
far away from any states that are able to carry current. In a metal, semimetal or degenerate semiconductor, μ lies within a delocalized band. A large...
There is also growing evidence of Lorentz violation in Weyl semimetals and Dirac semimetals. 4-vector Antimatter tests of Lorentz violation Fock–Lorentz...
umbilical sheathing layer. Unlike graphene, which is a two-dimensional semimetal, carbon nanotubes are either metallic or semiconducting along the tubular...
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