Page 16 - Materials Chemistry, Second Edition

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1.1. Historical Perspectives

Table 1.1. Natural Abundance of Elements in the Earth’s Crust a
Oxygen 46.1%
Silicon 28.2%
Aluminum 8.2%
Iron 5.6%
Calcium 4.2%
Sodium 2.4%
Magnesium 2.3%
Potassium 2.1%
Titanium 0.57%
Hydrogen 0.14%
Copper 0.005%
Total 99.8%
a [2]
Data taken from Reference .
(Table 1.1), it is not surprising that bronze was eventually abandoned for materials
applications. An iron silicate material, known today as wrought iron, was acciden-
tally discovered as a by-product from copper processing. However, this material was
softer than bronze, so it was not used extensively until the discovery of steel by the
Hittites in 1,400 B.C. The incorporation of this steel technology throughout other
parts of the world was likely an artifact of the war-related emigration of the Hittites
from the Middle East in 1,200 B.C. The Chinese built upon the existing iron-making
technology, by introducing methods to create iron alloys that enabled the molding of
iron into desired shapes (i.e., cast iron production). Many other empirical develop-
ments were practiced in this time period through other parts of the world; however, it
must be stated that it was only in the eighteenth and nineteenth century A.D. that
scientists began to understand why these diverse procedures were effective.
Figure 1.2 presents the major developmental efforts related to materials science,
showing the approximate year that each area was first investigated. Each of these areas
is still of current interest, including the design of improved ceramics and glasses,
originally discovered by the earliest civilizations. Although building and structural
materials such as ceramics, glasses, and asphalt have not dramatically changed since
their invention, the world of electronics has undergone rapid changes. Many new
architectures for advanced material design are surely yet undiscovered, as scientists
are now attempting to mimic the profound structural order existing in living creatures
and plant life, which is evident as one delves into their microscopic regimes.
As society moves onto newer technologies, existing materials become obsolete, or
their concepts are converted to new applications. A prime example of this is related
to phonographs that were commonplace in the early to mid-1900s. However, with
the invention of magnetic tape by Marvin Camras in 1947, there was a sharp drop in
record usage due to the preferred tape format. The invention of compact disk
technology in 1982 has driven the last nail in the coffin of records, which may
now only be found in antique shops and garage sales. The needles that were essential
to play records no longer have marketability for this application, but have inspired
another application at the micro-and nanoscale regime: atomic force microscopy,
more generally referred to as scanning probe microscopy (SPM, see Chapter 7).