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Unformatted text preview: d above.
region but above the martensite start Ms temperature.
band gap The forbidden range of electron energy
egate form such as sand and
levels located between the top of the valence band and
2.2 ATOMIC STRUCTURE
the bottom of the conduction band in a semiconductor or
All matter is composed of atoms. The atoms, in turn, consist of electrons, protons, and
that precipitates a second
neutrons. The properties of an atom are determined by many factors including: (1) the
d solid solution.
atomic number Z that correspondsor the number of electrons or protons in a neutral atom,
basal plane The top to bottom plane in a crystal. In
material that lacks the
(2) the mass of the atom, (3) the spatial distribution of the electrons in orbits around the
hexagonal crystals the basal plane is deﬁned by the atoms
nucleus, (4) the energy of the electrons in the atom, and (5) the ease of adding or removing
aracteristic of a crystalline
oneplaced on the six corners ofto create a charged ion. The latter three factors,
or more electrons from the atom hexagons. It is normal to the
s are either rubbers or glasses.
involving electrons, can be inﬂuenced by external conditions such as mechanical forces,
erties that vary with direction.
electromagnetic ﬁelds, and temperature. Since we are interested in the inﬂuence of exactly
basal slip Deformation that the bulk of the basal plane
these variables on the properties of solids, occurs on our discussion will focus on the
which the surface of a
of HCP of electrons a atoms. of dislocation of electron
characteristicscrystals as in result An understanding motion. behavior, however,
to a hard oxide by an
requires some understanding of quantum mechanics. Quantum mechanics theory, or
basis The number of atoms or by physicists in lattice
QMT, is a mathematical framework developedions on each the early part of the 20th
century to describe the interaction of electrons, protons, and neutrons in atoms and
ass of materials in which
bipolar junction transistor A solid-state
of equal strength poi...
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