Semimetal

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semimetal

[¦sem·ē′med·əl]
(chemistry)
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Semimetal

 

a substance occupying an intermediate position between metals and semiconductors with regard to electrical properties. A characteristic feature of semimetals is a weak overlapping of the valence band and conduction band. This indicates that semimetals remain conductors of electric current down to a temperature of absolute zero and yet have a low (compared to metals) concentration of current carriers—approximately 1018-1020 cm-3. Semimetals include Bi, Sb, As, and graphite.

Current carriers in semimetals exhibit high mobility and low effective mass. These properties make semimetals the most suitable substances for use in observing size effects, semimetal-dielec-tric phase transitions in strong magnetic fields, and many other phenomena.

REFERENCES

Fizika metallov. Vol. 1: Elektrony. Edited by J. Ziman. Moscow, 1972. (Translated from English.)
Lifshits, I. M., M. Ia. Azbel’, and M. I. Kaganov. Elektronnaia teoriia metallov. Moscow, 1971.
Fal’kovskii, L. A. “Fizicheskie svoistva vismuta.” Uspekhi fizicheskikh nauk, 1968, vol. 94, issue 1, p. 3.
Larson, D. C. “Razmernye effekty v elektroprovodnosti tonkikh metal-licheskikh plenok i provolok”. In Fizika tonkikh plenok, vol. 6. Moscow, 1973. (Translated from English.)

E. M. EPSHTEIN

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
For example, studies that evaluated lead or mercury are always displayed in the metals and semimetals broad category, and additionally appear in the air pollutants broad category when they were considered in the context of air pollution.
The Weyl fermions, which were observed in synthetic crystals of a semimetal called tantalum arsenide, exhibit some similar electronic properties to those found in the crystals used in the latest study, but lacked their chiral traits.
Graphene is a zero-bandgap semimetal, of which the valence band and conduction band meet at the Dirac points.
Allen, "Electronic structure of the semimetals Bi and Sb," Physical Review B, vol.
The properties of Weyl semimetals make them good candidates to produce not only Weyl fermions but Majorana particles as well, Xu says.
It is frequently considered as an assemblage name for metals and semimetals (metalloids) that have been linked with contamination and potential toxicity or ecotoxicity [1].
The existence of these valleys, each with a linear dispersion, is the main reason that graphene has transport properties which differ from most other semiconductors or semimetals. At high magnetic fields, a striking example is the quantum Hall effect, where the Hall conductance quantization occurs in steps of 4[e.sup.2]/h, because of the spin and valley degeneracy, and the Landau level quantization is proportional to [square root of (B)], where B is the perpendicular magnetic field component.
F., "Delta-doping of semiconductors: Electronic, optical, and structural properties of materials and devices," Semiconductors and Semimetals, Vol.
Heavy metals are chemical elements (metals and some semimetals) that have density higher than 5 g [cm.sup.-3], and atomic number higher than 20 (GONCALVES JUNIOR; PESSOA, 2002).
Browning, Overview of measurement and characterization techniques for TE materials, in Recent Trends in TE Materials Research I, Semiconductors and Semimetals, Vol.
Metals, unlike semimetals or nonmetals, are conductors of electricity and heat.
70, Semiconductors and Semimetals. San Diego: Academic Press, Inc., pp.