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Introduction to Nanotechnology

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BULK NANOSTRUCTURED<br />

MATERIALS<br />

In this chapter the properties of bulk nanostructured materials are discussed. Bulk<br />

nanostructured materials are solids having a nanosized microstructure. The basic<br />

units that make up the solids are nanoparticles. The nanoparticles can be disordered<br />

with respect <strong>to</strong> each other, where their symmetry axes are randomly oriented<br />

and their spatial positions display no symmetry. The particles can also be ordered<br />

in lattice arrays displaying symmetry. Figure 6. la illustrates a hypothetical<br />

two-dimensional ordered lattice of AI,2 nanoparticles, and Fig. 6.lb shows a two-<br />

dimensional bulk disordered nanostructure of these same nanoparticles.<br />

6.1. SOLID DISORDERED NANOSTRUCTURES<br />

6.1.1. Methods of Synthesis<br />

In this section we will discuss some of the ways that disordered nanostructured<br />

solids are made. One method is referred <strong>to</strong> as compaction and consolidation. As an<br />

example of such a process, let us consider how nanostructured Cu-Fe alloys are<br />

made. Mixtures of iron and copper powders having the composition Fe&uI5 are<br />

ballmilled for 15 h at room temperature. The material is then compacted using a<br />

<strong>Introduction</strong> <strong>to</strong> <strong>Nanotechnology</strong>, by Charles P Poole Jr. and Frank J. Owens<br />

ISBN 0-471-07935-9. Copyright (CJ 2003 John Wiley & Sons, Inc.<br />

133

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