Page 161 - Materials Chemistry, Second Edition

148 2 Solid-State Chemistry

route from the cathode to anode compartments of the fuel cell. By contrast, the
“holes” created by Y 3þ substitution may be envisioned to move in the opposite
direction, from the anode to cathode.

References and Notes

1
Zallen, R. The Physics of Amorphous Solids, John Wiley and Sons: New York. 1983.
2
Note: there is no empirical evidence that supports the flow of glass over time. That is, there is no
analogous glass thickening observed in ancient Roman or Egyptian objects, no degradation in the
optical performance of antique telescopes/microscopes, and no change in physical properties of
prehistoric artifacts (e.g., dulling of obsidian swords).
3
Note: electrons in an s-orbital have a finite probability of being found at the nucleus. As the principal
quantum number increases, the s-orbitals become more diffuse, leading to electrons being found at
distances further from the nucleus. With less attraction toward the nucleus, these electrons are able
to orbit the nucleus at speeds approaching the speed of light. When objects move at such high
speeds, an increase in relativistic mass occurs, whereby the s-electrons behave as though they were
more massive than electrons moving at slower speeds. This mass increase causes the orbiting
electrons to be slightly contracted toward the nucleus, decreasing their availability to participate
in chemical reactions.
4
Schroers, J.; Johnson, W. L. “History Dependent Crystallization of Zr 41 Ti 14 Cu 12 Ni 10 Be 23 Melts”
J. Appl. Phys. 2000, 88(1), 44–48, and references therein. More information may be obtained from
http://www.liquidmetal.com.
5
For example, see: Dera, P.; Lavina, B.; Borkowski, L. A.; Prakapenka, V. B.; Sutton, S. R.; Rivers,
M. L.; Downs, R. T.; Boctor, N. Z.; Prewitt, C. T. Geophys. Res. Lett. 2008, 35, L10301.
6
(a) Malone, B. D.; Sau, J. D.; Cohen, M. L. Phys. Rev. B 2008, 78, 161202, and references therein.
(b) Pfrommer, B. G.; Cote, M.; Louie, S. G.; Cohen, M. L. Phys. Rev. B 1997, 56, 6662, and references
therein.
7
There is an ongoing debate whether the term “pseudopolymorph” should be abandoned, instead
designating these compounds as “solvates”. Two viewpoints may be found at: (a) Bernstein, J.
Cryst. Growth Design 2005, 5, 1661. (b) Nangia, A. Cryst. Growth Design 2006, 6,2.
8
For a nice presentation regarding the thermal characterization of polymorphs, and the implications of
polymorphism toward drug design, see: http://www.usp.org/pdf/EN/meetings/asMeetingIndia/
2008Session1track3.pdf
9
For example, see: Perrillat, J. P.; Daniel, I.; Lardeaux, J. M.; Cardon, H. J. Petrology 2003, 44, 773.
May be found online at: http://petrology.oxfordjournals.org/cgi/content/full/44/4/773
10
(a) For instance, the high-pressure polymorphism of silica is described in: Teter, D. M.; Hemley,
R. J. Phys. Rev. Lett. 1998, 80, 2145; also available online: http://people.gl.ciw.edu/hemley/
192TeterPRL 1998.pdf. (b) McMillan, P. F.; Wilson, M.; Daisenberger, D.; Machon, D. Nature
Mater. 2005, 4, 680.
11
Note: the Miller indices for the (211) plane may also be visualized by extending the unit cell beyond a
cell volume of 1 cubic unit. For instance, equivalent planes would also pass through (2,0,0), (0,4,0),
and (0,0,4), as well as other extended coordinates. For the (001) plane, the zeroes indicate that the
plane does not intercept either the a or b axes.
12
Cullity, B. D. Elements of X-ray Diffraction, 2nd ed., Addison-Wesley: Reading, Massachusetts, 1978.
13
For a comprehensive list of SiC physical properties, see: http://www.ioffe.ru/SVA/NSM/Semicond/
SiC/bandstr.html#Band
14
For more details about the structure and applications of SiC, see: http://www.ifm.liu.se/matephys/
new_page/research/sic/index.html