Welcome to 3.091 Lecture 13

October 9, 2009

Band Theory of Solids

properties of metallic solids:

high electrical conductivity high thermal conductivity luster ductility

what is it about their electronic structure???

Free-electron Gas Model

Paul Drüde (1900)

Sea of delocalized, mobile valence electrons

Cations in an ordered array

Image by ARTE on Wikipedia.

5

Zs. f. Phys., 44, 455-472 (1927)

Text removed due to copyright restrictions. Please see p. 462 from Heitler, W., and F. London. "Wechselwirkung neutraler Atome und homöopolare Bindung nach der Quantenmechanik." Zeitschrift für Physik A: Hadrons and Nuclei 44 (1927): 455-472.

© Springer. All rights reserved. This content is excluded from our Creative Commons license. For more information, see http://ocw.mit.edu/fairuse. Source: Fig. 1 in Heitler, W., and F. London. "Wechselwirkung neutraler Atome und homöopolare Bindung nach der Quantenmechanik." Zeitschrift für Physik A: Hadrons and Nuclei 44 (1927): 455-472.

antibonding

bonding

© Springer. All rights reserved. This content is excluded from our Creative Commons license. For more information, see http://ocw.mit.edu/fairuse.Source: Fig. 1 in Heitler, W., and F. London. "Wechselwirkung neutraler Atome und homöopolare Bindung nach der Quantenmechanik." Zeitschrift für Physik A: Hadrons and Nuclei 44 (1927): 455-472.

Figure 12.21

Averill, B., and P. Eldredge. Chemistry: Principles, Patterns, and Applications. Flat World Knowledge, 2011. ISBN: 9781453331224.

Be

Be

Courtesy of Daniel Nocera. Used with permission.

Image by MIT OpenCourseWare.

Image by Pieter Kuiper on Wikipedia.

207.2327.46174911.342.337.416[Xe]4f145d106s2p2

Lead

12.0114492TP

3825SP

2.252.5511.260[He]2s2p2

Carbon

72.61938.2528335.352.017.899[Ar]3d104s2p2

Germanium

118.710231.9326027.281.967.344[Kr]4d105s2p2

Tin

82

Pb2,4

50

Sn2,4

28.0855141432652.331.908.151[Ne]3s2p2

Silicon

14

Si4

32

Ge4

6

C2, 4-

Eg = Eg (z) in group 14

5.4

1.1

0.72

0.08

0

(eV)

Insulator

Semiconductors

Metal

Image by MIT OpenCourseWare.

207.2327.46174911.342.337.416[Xe]4f145d106s2p2

Lead

12.0114492TP

3825SP

2.252.5511.260[He]2s2p2

Carbon

72.61938.2528335.352.017.899[Ar]3d104s2p2

Germanium

118.710231.9326027.281.967.344[Kr]4d105s2p2

Tin

82

Pb2,4

50

Sn2,4

28.0855141432652.331.908.151[Ne]3s2p2

Silicon

14

Si4

32

Ge4

6

C2, 4-

Eg = Eg (z) in group 14

5.4

1.1

Eg 0.72

0.08

0

as n

(eV)

Image by MIT OpenCourseWare.

MIT OpenCourseWare http://ocw.mit.edu

3.091SC Introduction to Solid State Chemistry Fall 2009

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