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Silica Dioxide
Crystal: SiO2
Structure: Various, here: a = trigonal and b = hexagonal
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Cohesive energy: |
eV |
Lattice parameter: |
Å |
Density: |
g/cm3 |
Stiffness constants: in 1011 dynes/cm2, at room temperature
a |
b |
|
c11: |
8.76 |
11.66 |
c12: |
0.67 |
1.67 |
c44: |
5.72 |
3.606 |
c33: |
10.68 |
11.04 |
Fused quartz: third and fourth order elastic constants.:
K-i Kondo, S. Iio, A. Sowaoka, J. Appl. Phys. 52, 2827 (1981)
Poisson ratio:
Compressibility (in 1011 dynes/cm2):
p11: 7.8394
p44: 3.1261
p111: 52.6
p112: 23.9
p123: 5.4
Debye temperature: 290 K for
a , see also Ref.2Melting temperature: see Ref.3
Neel temperature: K
Phonon spectrum discussed by: see Phys. Rev. B12, 4553 (1975) for
aTemperature dependence of phonons: See J. Phys. C15, 3821 (1982)
Phonon dispersion in quartz: See J. Phys. C13, 6607 (1980)
Transverse optic phonon T0 (k=0): see Phys. Rev. B11, 3944 (1975)
Longitude optic phonon L0 (k=0): see Phys. Rev. B13, 5525 (1976)
Gruneissen constant:
Polaron coupling constant:
a = ( for m*=1 )Ratio e*/e:
Band gap:
direct: eV.
indirect: eV.
Gap: eV.
First exciton: eV.
SiO2 absorption edge, exciton resonances:
R.B. Laughlin, Phys. Rev. B22, 3021 (1980) which gives: Band Gap Eg = 8.9 eV.
SiO2-polymorphs-Valence forces, lattice vibrations: See J. Chem. Phys. 68, 1531 (1978)
Valence bond forces: see Phys. Rev. B17, 2790 (1978)
Valence band density of states: Tagle et al., Surf. Sci. 81, 5189 (1979)
Electron levels: Phys. Rev. B10, 710 (1974)
Charge transport: see Nature 256, 12 (03/07/1975)
Electron: - band like
- small polaron in non-bonding orbital: ~0.6 eV. Ea
See Phys. Rev. Letters 27, 1560 (1971) for theory
Also: Appl. Phys. Letters 26, 436 (1975)
Free energy of SiO2 (vitreous, various models) relative to crystalline. Bond enthalpies: D.G. Howitt, D.K. McElfresh, Phys. Chem. Glasses 23, 107 (1982)
Band structure discussed by: Pantelides and Harrison, Phys. Rev.B13,2667 (1976)
Static dielectric constant: at 300K, for
Optic dielectric constant: 2.40 for
aLinear dispersion of transverse phonons to 450 Ghz: Phys. Rev. B27, 5196 (1983)
Electron mobility:
Hole mobility:
Effective mass:
conduction band:
valence band:
Electron affinity: (in eV., from bottom of conduction band under vacuum)
SiO2 electron transport breakdown:
m(p)~ 1.3 m(o) seems the best
Ref.: D.K. Ferry, J. Appl. Phys. 50, 1422 (1979)
Spin-orbit coupling: (valence band)
Cation polarisation: Å-3
Anion polarisation: Å-3
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Other information:
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References:
1. J. Appl. Phys. 49, 4776
2. Geophys. J. Roy. Astronom. Soc. 32, 15 (1973)
3. J. Geophys. Res. 81, 2453 (1976)
4. J. Appl. Phys. 45, 2852 (1974)
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