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Molecules & Solids. Harris Ch 9 Eisberg & Resnick Ch 13 & 14 RNave: http://hyperphysics.phy-astr.gsu.edu/hbase/solcon.html#solcon Alison Baski: http://www.courses.vcu.edu/PHYS661/pdf/01SolidState041.ppt Carl Hepburn, “Britney Spear’s Guide to Semiconductor Physics”.
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Molecules & Solids Harris Ch 9 Eisberg & Resnick Ch 13 & 14 RNave: http://hyperphysics.phy-astr.gsu.edu/hbase/solcon.html#solcon Alison Baski: http://www.courses.vcu.edu/PHYS661/pdf/01SolidState041.ppt Carl Hepburn, “Britney Spear’s Guide to Semiconductor Physics”. http://britneyspears.ac/lasers.htm
http://hyperphysics.phy-astr.gsu.edu/hbase/solcon.html#solconhttp://hyperphysics.phy-astr.gsu.edu/hbase/solcon.html#solcon
Harris Sections • Bonding in Molecules (9.1-9.2) • Rotation and Vibration in Molecules (9.3) • Types of Solids & Crystals (9.4) • Nearly Free-Electron Model (9.5) • Conductors, Insulators, Semiconductors (9.6-9.9) • Superconductivity (9.10)
Four Closely Spaced Atoms conduction band valence band
N closely-spaced Atoms the level of interest has the same nrg in each separated atom Harris 9.2
Two atoms Six atoms Solid of N atoms ref: A.Baski, VCU 01SolidState041.ppt www.courses.vcu.edu/PHYS661/pdf/01SolidState041.ppt
Solid composed of ~NA Na Atomsas fn(R) 1s22s22p63s1
Sodium Bands vs Separation Rohlf Fig 14-4 and Slater Phys Rev 45, 794 (1934)
Copper Bands vs Separation Rohlf Fig 14-6 and Kutter Phys Rev 48, 664 (1935)
Differences down a column in the Periodic Table: IV-A Elements same valence config Sandin
Bonding http://hyperphysics.phy-astr.gsu.edu/hbase/chemical/chemcon.html#c1 R Nave, Georgia State Univ
Chemical Bonding http://hyperphysics.phy-astr.gsu.edu/hbase/chemical/bondcon.html#c1 R Nave, Georgia State Univ
Ionic Bonds RNave, GSU at http://hyperphysics.phy-astr.gsu.edu/hbase/chemical/bond.html#c4
Covalent Bonds RNave, GSU at http://hyperphysics.phy-astr.gsu.edu/hbase/chemical/bond.html#c4
Covalent Bonding SYM ASYM spatial spin ASYM SYM spatial spin s* s
Covalent Diatomic Level Diagram Harris Fig 9.8
Covalent Bonding not really parallel, but spin-symmetric Stot = 1 Stot = 0 not really anti, but spin-asym E&R
Covalent Two atoms Six atoms Solid of N atoms ref: A.Baski, VCU 01SolidState041.ppt www.courses.vcu.edu/PHYS661/pdf/01SolidState041.ppt
Covalent Bonding with p-orbitals Harris 9.9 & 9.10
Bonding with p-orbitals Harris 9.11
Bonding Dissimilar Atoms-- broken symmetry H 9.14 & Table 9.1
Ionic Characteristics Crystalline solids High melting & boiling point Conduct electricity when melted Many soluble in water, but not in non-polar liquids Covalent Characteristics Gases, liquids, non-crystalline solids Low melting & boiling point Poor conductors in all phases Many soluble in non-polar liquids but not water Ionic vs Covalent Bond Properties
Ionic Bonds RNave, GSU at http://hyperphysics.phy-astr.gsu.edu/hbase/chemical/bond.html#c4
Ionic Bonding RNave, Georgia State Univ at hyperphysics.phy-astr.gsu.edu/hbase/molecule
Covalent Bonds RNave, GSU at http://hyperphysics.phy-astr.gsu.edu/hbase/chemical/bond.html#c4
Covalent Bonding SYM ASYM spatial spin ASYM SYM spatial spin space-symmetric tend to be closer
Covalent Bonding not really parallel, but spin-symmetric Stot = 1 Stot = 0 not really anti, but spin-asym space-symmetric tend to be closer
Molecular ExcitationsRotation, Vibration, ElectricHarris 9.3
Rotational Spectra w rotational A.M. moment of inertia
Ocean Optics: Nitrogen N2 ~ 0.3 eV ~ 0.4 eV
Electronic + Vibration + Rotation 2.550 eV 2.656 eV electronic excitation gap vibrational excitation gaps
Electronic + Vibration + Rotation Vibrational Well Vibrational Well 2.656 eV depth ~ 0.063 eV electronic excitation gap vibrational excitation gaps
Electronic, Vibration, Rotation Electronic ~ optical & UV ~ 1 – 3 eV Vibration ~ IR ~ 10ths of eV Rotation ~ microwave ~ 1000ths of eV Harris 9.24