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Sodium Iodide

 

Crystal: NaI

Structure: NaCl

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Lattice formation energy:

-7.08 eV.

Lattice parameter:

3.23 Å (3.194 at 0K.)

Density:

g/cm3

 

 

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

 

c11: 3.59 (Ref.1)

or 3.761

c12: 0.75

or 0.798

c44: 0.768

or 0.781

 

Compressibility (in 1011 dynes/cm2): 0.589

Poisson ratio:

 

Debye temperature: 165 K

Melting temperature: K

 

Phonon spectrum discussed by:

A.D.B Woods, W. Cochran & B.N. Brockhouse, Lattice dynamics of alkali halide crystals, Phys.Rev. 119, 980 (1960)

And: A.D.B.Woods,B.N. Brockhouse & R.A. Cowley, Lattice dynamics of alkali halide crystals.II: Studies of KBr & NaI, Phys. Rev. 131, 1025 (1963)

 

Transverse optic phonon T0 (k=0): 113.5 or 124 cm-1

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

 

Gruneissen constant:

Ratio e*/e: 0.71

 

Photoelastic constants:

p11:

p12:

p44:

 

 

Band gap:

direct: 5.8 eV. at K

indirect: eV. at ° K

 

Plasmon energy: eV.

Exciton energy: 5.61 eV. (Ref.2)

Conduction band width: 1.5eV.

 

Band structure discussed by:

 

Static dielectric constant: 6.60 or 6.62

Optic dielectric constant: 2.91 or 3.08

 

Electron mobility:

Hole mobility:

Polaron coupling constant: a = 4.8 ( for m*=1 )

Effective mass: conduction band:

valence band:

 

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

3.21, by Mott-Gurney, perhaps 3eV. too high (Ref.3)

 

Spin-orbit coupling: 1.17 ( valence band) (Ref.4)

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Other information:

 

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References:

 

  1. R. Dalven and C. W. Garland Elastic constants of Sodium Iodide from 180K. to 300K. J.Chem.Phys. 30, 346 (1959)

    2.  

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

    3.  

  3. N.F. Mott & R.W. Gurney, "Electronic processes in Ionic crystals", 2nd. Edition (1950)

    4.  

  4. J.E. Eby, K.J. Teegarden & D.B. Dutton, Ultraviolet absorption of alkali halides Phys.Rev. 116, 1099 (1959)

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