Info Hof
Figure 2.13. Sketch of a unit cell in two-dimensional x,y coordinate space and b corresponding Brillouin zone in reciprocal space kx, ky for a rectangular Bravais lattice. 2.2.3. Energy Bands and Gaps of Semiconductors The electrical, optical, and other properties of semiconductors depend strongly on how the energy of the delocalized electrons involves the wavevector k in reciprocal or k space, with the electron momentum p given by p mv Jik, as explained above. We will consider...
Supramolecular Dendrimers
Individual dendritic compounds can be linked together to form larger structures called supramolecular deruirimers, and this linking procedure can be carried out by a process called supramolecular self-assembly. As an example consider the dendrimer in die upper left corner of Fig. 11.20, in which die core consists of a central benzene ring associated with a complicated aromatic, polycyclic complex attached 'above it, plus two branched wedges shown bifurcated below it To simplify die notation,...
Insulator
Figure 5.22. Illustration of the concept of a computer switching device made from carbon nanotubes. Adapted from C. M. Lieber, Sd. Am., 59 Sept. 2001 . Another idea that is being pursued is to make a computer out of carbon nanotubes. The computer would be an array of parallel nanotubes on a substrate. Above this, but not touching the lower array and having a small separation from them, are carbon nanotubes tubes oriented perpendicular to the tubes on the substrate. Each tube would be connected...
Further Reading Rsz
A. Clearfield, Preparation of Pillared Clays and Their Catalytic Properties, in Moser 1996 , Chapter 14, p. 345. A. Lerf, Intercalation Compounds in Layered Host Lattices Supramolecular Chemistry in Nanodimensions, in Nalwa 2000 , Vol. 5, Chapter 1, p. 1. W. R. Moser, ed., Advanced Catalysts and Nanostructured Materials, Academic Press, San Diego, 1996. H. S. Nalwa, ed., Handbook of Nanostructured Materials and Nanotechnology, Vols. 1-5, Academic Press, Boston, 2000. S. Sugano and H. Koizumi,...
C W 7 o
Figure 2.1. The five Bravais lattices that occur in two dimensions, with the unit cells indicated a square b primitive rectangular c centered rectangular d hexagonal e oblique. Figure 2.2. Sketch of a two-dimensional crystal structure based on a primitive rectangular lattice containing two diatomic molecules A-B in each unit cell. A crystal structure is formed by associating with a lattice a regular arrangement of atoms or molecules. Figure 2.2 presents a two-dimensional crystal structure based...