Metalloid

A metalloid is a chemical element semi-metal, i.e. whose physical properties and chemical are intermediate between those of a Métal and of a Non-métal.

Differentiation between metalloid and metal takes into account several criteria, but the majority of metalloids are Semi-conducteur S rather than of the conducting .

There exists an even number of electrons per cell unit, so that the bands of valence should be filled, and them unoccupied bands of conduction, which would give place to a semiconductor. However, in a semi metal, the highest valence band and the band of the lowest conduction are recovered. It results from it that all the states of the highest valence band are not occupied, and the states of the band of the lowest conduction are partially occupied. So a semi-metal is a driver in which the charge carriers are either of the holes in the valence band or of the electrons in the band of conduction. It is possible by applying a pressure to modify the structure of band of a material to produce a transition semiconductor semi-metal.

The metalloids are gathered in the same triangular zone of the periodic Tableau of the elements; it is:

References

  • W.R. Datars and J. Vanderkooy '' IBM J. Res. Dev. 8, 247 (1964) ''

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