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Sodium Bromide
Crystal:
Structure: NaCl
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Lattice formation energy: |
-7.53 eV. |
Lattice parameter: |
2.98 Å (2.954 at 0K.) |
Density: |
3.299 g/cm3 at 4K. |
Stiffness constants: in 1011 dynes/cm2, at room temperature
c11: 3.970 (4.800 at 4K.) (Ref.1)
c12: 1.001 (0.986 at 4K.)
c44: 0.998 (1.070 at 4K.)
Compressibility (in 1011 dynes/cm2): 0.5023 ??
Poisson ratio:
Debye temperature: 225 K
Melting temperature: K
Phonon spectrum discussed by:
J.S. Reid & T. Smith, Phonon frequencies in NaBr, Phys. Rev. B1, 1833 (1970)
Transverse optic phonon T0 (k=0): 134 or 146 cm-1
Longitude optic phonon L0 (k=0): cm-1
Gruneissen constant:
Ratio e*/e: 0.69
Photoelastic constants:
p11:
p12:
p44:
Band gap:
direct: 7.1 eV. at K
indirect: eV. at ° K
Plasmon energy: 14.2 eV.
Exciton energy:
7.7 eV. (Ref.2)
6.71 eV. (Ref.3)
Electronic band structure of the alkali halides. II: Critical survey of theoretical calculation, R.T. Poole, J. Liesegang, R.C.G. Leckey & J.G. Jenkin, Phys. Rev. B11, 5194 (1975) which gives:
Valence band width: |
3.8 eV. |
Gap: |
7.5 eV. |
Electron affinity: |
0.4 eV. |
Band structure discussed by:
A. B. Kunz, N. O. Lipari, Electronic structure of NaBr, Phys.Rev. B4, 1374 (1971)
Static dielectric constant: 5.78
Optic dielectric constant: 2.64
Electron mobility:
Hole mobility:
Polaron coupling constant:
Effective mass: conduction band:
valence band:
Electron affinity: ( in eV., from bottom of conduction band under vacuum)
3.51, by Mott-Gurney, maybe 3eV. too high (Ref.4)
Spin-orbit coupling: 0.52 ( valence band) (Ref.5)
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Other information:
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References:
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