Page 18 - Materials Chemistry, Second Edition

5
1.2. Considerations in the Design of New Materials

Figure 1.3. A 40-nm wide logo for NIST (National Institute of Standards and Technology), made by the
manipulation of Co atoms on a Cu(111) surface. The ripples in the background are due to electrons in the
fluid-like layer at the copper surface, bouncing off the cobalt atoms – much like the patterns produced
when pebbles are dropped in a pond. Image provided courtesy of J. A. Stroscio and R. J. Celotta (NIST,
Gaithersburg, MD).

discoveries including the keys to immortality, a “philosopher’s stone” to transform
base matter into higher matter, methods to synthesize gold (or transform any other
metal into gold), and magic potions to cure diseases. However noble these pursuits
were, they remained unaccomplished due to the lack of an underlying chemical
theory to guide their experimentation. In addition, their trial-and-error methodology
involved only qualitative characterization, and it was extremely difficult to control
the reaction conditions, making it virtually impossible to repeat the exact procedure
a number of times.
As a result, from 1,000 B.C. to 1,700 A.D., only a few new substances were
discovered which later turned out to be elements such as copper, iron, and mercury.
Although this foundationresulted in the development of many experimental techniques
of modern chemistry, it is not hard to see that true progress toward new material design
may only be accomplished through foresight, based on an intimate understanding of
specific relationships between the structure and property of a material. However, as you
will see throughout this text, even with such knowledge, many important materials
discoveries have been made by accident – the result of an unplanned occurrence during
a carefully designed synthesis of an unrelated compound!

1.2. CONSIDERATIONS IN THE DESIGN OF NEW MATERIALS

The development of new materials is governed by the current societal need and
availability of resources. However, the adoption of a material depends primarily
on its cost, which is even observed by changes in the chemical makeup of currencies
through the years. Coins currently comprise worthless ferrous alloys rather than high
concentrations of metals such as gold, silver, copper, and nickel that comprised early
coins. When a new technology or material is introduced, there is almost always
a high price associated with its adoption. For example, consider the cost of compu-
ters and plasma televisions when they first became available – worth tens of
thousands of dollars!