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Silver Bromide
Crystal:
AgBrStructure: NaCl
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Lattice formation energy: |
-8.56 eV. (theory, Mayer and al.) (Ref.1) |
-8.77 eV. (experimental) (Ref.1) |
|
Lattice parameter: |
2.884 Å (Ref.2) |
Density: |
6.47 g/cm3 (Ref.2) |
Stiffness constants: in 1011 dynes/cm2, at room temperature
c11: 5.62 (Ref.2)
c12: 3.28
c44: 0.73
Compressibility (in 1011 dynes/cm2): 0.246 ??
Poisson ratio:
Mixed AgCl/AgBr elastic constants:
The elastic constants & their temperature and pressure derivatives of AgBr-AgCl mixed crystals, L.S. Cain, J.Phys.Chem.Solids 38, 73 (1977)
Debye temperature: K
Melting temperature: K
Phonon spectrum discussed by:
K. Fischer, H. Biltz, R. Haberkorn & W. Weber, Covalency & deformability of Ag+ ions in the lattice dynamics of Silver halides, Phys.Stat.Sol. 54, 285 1972)
(Includes covalency & shell model)
Also: Y. Fujii, S. Hoshino, S. Sakuragi & H. Kanzaki, Neutron scattering study of the lattice dynamics of AgBr at 4.4K., Phys. Rev. B15, 358 (1977)
Also: See Bloch thesis for earlier work
Phonons studies:
Excitons & phonons in mixed Silver halides studied by resonant Raman scattering, A. Fujii, H. Stolz & W. von der Osten, J.Phys. C16, 1713 (1983)
Note: for Cl/Br, inversion of at L point
Transverse optic phonon T0 (k=0): ~140 cm-1 (Not the 119 cm-1 assumed by Brandt & Brown)
Longitude optic phonon L0 (k=0): 132 cm-1 (Hodby)
Gruneissen constant:
Ratio e*/e: 0.73
Photoelastic constants:
p11:
p12:
p44:
Band gap:
direct: 4.25 eV. (L) , 6.14 eV. (Gamma)
indirect: 2.68 eV. at ° K
Plasmon energy: eV.
Exciton energy: 4.25 eV. (Gamma) at 20K. (Ref.3), 6.1 eV. (L) at 20K.
Stolz & Wassmuth give also:
g(c)= 1.46 eV
g(v)= 2.61 eV
Exchange : 0.17 meV.
Indirect exciton B.E.: 32 meV.
Indirect Gap: 2.8 eV. (Cond. band at zone centre, Valence band at L point)
Direct Gap: 4.29 eV.
Band structure discussed by:
H. Stolz, W. Wassmuth, W. von der Osten & C. Uihlein, Resonant Raman scattering at the indirect triplet exciton in AgBr in high magnetic fields, J. Phys. C16, 955 (1983)
Photoemission:
Silver-halide valence & conduction states: temperature-dependence ultraviolet emission studies, R.S. Bauer & W.E. Spicer, Phys.Rev. B14, 4539 (1976)
Static dielectric constant: 10.60 (Hodby) or 10.64 at 2K. and 12.64 at 255K. (Ref.4)
Optic dielectric constant: 4.68 (Ref.3)
Electron mobility:
Hole mobility:
Polaron coupling constant:
Effective mass:
conduction band: m*(e): 0.288 (ref 5)
valence band: m*(h): 1.123 (ref 5)
Exciton mass: 0.229 (Ref.5)
Polaron radius: 17 Å
Deformation potential: ~2 eV.
Electron affinity: ( in eV., from bottom of conduction band under vacuum)
Spin-orbit coupling: 0.6 eV. ( valence band)
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References:
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