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Barium Oxide
Crystal: BaO
Structure: NaCl
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Lattice parameter: |
2.76 Å |
Density: |
g/cm3 |
Stiffness constants
: in 1011 dynes/cm2, at room temperature
c11: See Ref. 1, 2
c12:
c44:
Compressibility (in 1011 dynes/cm2):
Poisson ratio:
Debye temperature: 272 K
Melting temperature: 1380 ° C (sublimes) 1928 or 1917
Phonon spectrum discussed by: see J. Phys. Chem. Soc. July/Aug. 1975
Transverse optic phonon T0 (k=0): Parodi cites 189 cm-1 IR abs.
Longitude optic phonon L0 (k=0): cm-1
Gruneissen constant:
Ratio e*/e:
Photoelastic constants:
p11:
p12:
p44:
Band gap: direct: 4.0 or 4.8 eV (Henderson & Hughes) or 3.95 (Bessent)
First exciton: 4.06 eV. (Ref.3)
Valence band width: 8.4 eV
(Mott-Gurney,"Electronic processes in Ionic crystals", 2nd. Edition (1950))
Band structure discussed by:
Static dielectric constant: 34 (NOT 14.4)
Optic dielectric constant: 3.83
Electron mobility:
Hole mobility:
Polaron coupling constant:
Effective mass:
conduction band:
valence band:
Electron affinity: ( in eV., from bottom of conduction band under vacuum)
0.5 (Ref.4) or 0.57 (Ref.5)
Spin-orbit coupling: ( valence band)
Cation polarisation: 1.550 Å-3
Anion polarisation: 3.050 Å-3
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References:
1. V.H. Vetter, R.A. Bartels BaO single crystal elastic constants and their temperature dependence, J. Phys. Chem.S ol. 34, 1448 (1973)
2. Z. Chang, E.K. Graham Elastic properties of oxides in the NaCl-Structure, J. Phys. Chem. Soc. 38, 1355 (1977)
3. B. Ulrici, W. Ulrici, N.N. Kovalev Optical absorption in SrO single crystals, Sov. Phys. Sol. St. 17, 2305 (1976)
4. S. 60, 13 (1948)
5. K.Y. Tsou and E.B. Hensley Electron affinities of the alkaline earth chalcogenides, J. Appl. Phys. 45, 47 (1974)
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