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Lithium Iodide

Crystal: LiI

Structure: NaCl

Also Wurtzite and amorphous

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Lattice formation energy:

-7.71 eV

Lattice parameter:

3.00 Å (2.951 at 0K.)

 

nn distance for Wurtzite structure is 2.74 Å (Ref.1), with a=4.48 Å c=1.62 Å

Density:

g/cm3

 

 

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

 

c11: 2.922 (adiabatic, Ref.2)

or 2.707 (at 295K., isothermal, Ref.3)

c12:1.428

or 1.221

c44: 1.415

or 1.407

 

Compressibility (in 1011 dynes/cm2): 0.519 ??

Poisson ratio:

 

Debye temperature: 200.5 K (Ref.4)

Melting temperature: K

 

Phonon spectrum discussed by:

From Hashimoto & Kanzaki:

Absorption of phonon at ~ 5.6-6 eV.

Emission at 9.5eV.

 

Transverse optic phonon T0 (k=0): 151.5 cm-1

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

 

Gruneissen constant:

Ratio e*/e:

 

Photoelastic constants:

p11:

p12:

p44:

 

 

Band gap:

direct: eV. at K

indirect: eV. at ° K

 

Plasmon energy:

Exciton energy:

5.94 eV. (Ref.5)

also 6.80 eV. peak, i.e. 0.86 eV. doublet spitting (Ref.6)

 

For Wurtzite structure:

exciton: 6.12 eV. (Ref.6)

7.10 eV. Peak

0.98 eV. doublet splitting

 

For amorphous structure:

exciton 5.85 eV. (Ref.6)

6.95 eV. peak1.

10 eV. doublet splitting

 

Band structure discussed by: A.B. Kunz, Self-consistent local orbitals for Lithium Halide Crystals, Phys.Rev. B2, 2224 (1970)

 

Static dielectric constant: 11.03 or 16.85 (Ref.7)

Optic dielectric constant: 3.80 or 3.80

 

Electron mobility:

Hole mobility:

Polaron coupling constant: a = 2.4 ( for m*=1 )

Effective mass: conduction band:

valence band:

 

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

 

Spin-orbit coupling: 1.23 (theory) (valence band)

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References:

  1. W. Ruhl, Zur Struktur dunner, bei tiefer Temperatur kondensierter Salzschichten, I: Alkalihalogenide Zeit. fur Phys. 143, 591 (1956)

    2.  

  2. K.O. Mc.Lean & C.S. Smith, LiI elastic constants & temperature derviatives at 295K., J.Phys.Chem.Solids 33, 275 (1972)

    3.  

  3. W.T. Berg, Low temperature heat capacities of Silver Chloride & Lithium Iodide, Phys.Rev. B13, 2641 (1976)

    4.  

  4. Excitonenspectren des LiJ und seiner Hydrate, Von F. Fischer & R. Hilsch Zeitschrift fur Physik, 158, 553 (1960)

    5.  

  5. W.B. Fowler, "Physics of Color Centers", New York: Academic Press (1968)

    6.  

  6. Zeitschrift fur Naturforschung, A12, 445 (1957)

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