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Silver Iodide

Crystal: AgI

Structure: Various, here Wurtzite

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Mechanical and structural properties:

Lattice formation energy:	-8.25 eV. (theory, Mayer and al.) (Ref.1)
	-8.65 eV. (experimental) (Ref.1)
Lattice parameter:	Å
Density:	g/cm³

Stiffness constants: in 10¹¹ dynes/cm², at room temperature

c₁₁: 2.93 (Ref.2)

c₁₂: 2.13

c₄₄: 0.373

Compressibility (in 10¹¹ dynes/cm²): 0.417 ??

Poisson ratio:

Debye temperature: K

Melting temperature: K

Phonon spectrum discussed by:

G. Burns, F.H. Dacol & M.W. Shafer, Results from Raman spectra of the superionic conductor AgI, Phys. Rev. B16, 1417 (1977)

Also: See Ref.3, 4, 5, 6

Transverse optic phonon T0 (k=0): cm^-1

Longitude optic phonon L0 (k=0): cm^-1

Gruneissen constant:

Ratio e*/e:

Photoelastic constants:

p₁₁:

p₁₂:

p₄₄:

Electronic properties:

Band gap:

direct: ~2 eV. (?) at K

indirect: eV. at ° K

Plasmon energy: eV.

Exciton energy: eV.

Photoemission:

Silver-halide valence & conduction states: temperature-dependence ultraviolet emission studies, R.S. Bauer & W.E. Spicer, Phys.Rev. B14, 4539 (1976)

See also:

D.E. Eastman, W.D. Grobman, J.L. Feeouf & M. Erbudak, Photoemission spectroscopy using synchrotron radiation. I: Overviews of valence-band structure for Ge, GaAs, GaP, InSb, ZnSe, CdTe & AgI, Phys. Rev. B9, 3473 (1974)

Band structure discussed by:

Static dielectric constant:

Optic dielectric constant:

Electron mobility:

Hole mobility:

Polaron coupling constant: a = ( for m*=1 )

Effective mass:

conduction band:

valence band:

Electron affinity: ( in eV., from bottom of conduction band under vacuum)

Spin-orbit coupling: ( valence band)

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Other information:

Phase diagram: Vedam et al. in: "Phase transition"

AgI (poor) neutron data: Alpha-AgI: Structural disorder (bccI lattice + random Ag)

Sigma: ~1.3-2.6/Ohm.cm.

Diffusion D: ~2.10exp(-5) cm2/sec. at 250 ° C

Beta AgI is hexagonal

Ref.: K. Funke, J. Kalus, R. E. Lechner, Quasielastic and inelastic scattering of cold neutrons from Silver Iodide, Sol. State Com. 14, 1021 (1974)

Raman scattering by 5 phases of AgI:

R.C. Hanson, T.A. Fjeldly & H.D. Hochheimer, Raman scattering from five phases of Silver Iodide, Phys. Stat. Solidi 70, 567 (1975)

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References:

1. C. Kittel, "Introduction to Solid State Physics", 2nd. Edition, New York: Wiley (1956)

2. T.A. Fjeldly, Elastic & piezoelectric constants of Silver Iodide: Study of a material at the covalent-ionic phase transition, Phys. Rev. B10, 3569 (1974)

3. G. Burns, F. H. Dacol, M. W. Shafer, Raman measurements of the superionic conductor AgI

4. M.J. Delanay and S. Ushioda, Raman spectra of silver-halide melts and sublattice melting in the superionic conductor Alpha-AgI, Phys. Rev B16, 1410 (1977)

5. R. Alben & G. Burns, Lattice dynamics of the superionic conductor AgI, Phys. Rev. B16, 3746 (1977)

6. W. Buhrer, R.M. Nicklow & Bruesch, Lattice dynamics of beta-(Silver Iodide) by neutron scattering,, Phys. Rev. B17, 3362 (1978)

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