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Potassium Iodide

Crystal: KI

Structure: NaCl

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Lattice formation energy:

-6.50 eV.

Lattice parameter:

3.52 Å (3.489 at 0K.)

Density:

g/cm3

 

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

 

c11: 2.67 or 3.38 or 2.69

c12: 0.43 or 0.22

c44: 0.421 or 0.368 or 0.362

 

Compressibility (in 1011 dynes/cm2): 0.849 ??

Poisson ratio:

 

Debye temperature: 131 K

Melting temperature: K

 

Phonon spectrum discussed by:

G. Dolling, R.A. Cowley, S. Schittenhelm & I.M. Thorson, Normal vibrations of Potassium Iodide, Phys.Rev. 147, 577 (1966)

Phonons: experiments + breathing shell:

Phonon dispersion in the mixed crystal K0.5Rb0.5I, B. Renker, N.M. Butt & N.E. Massa, Phys.Rev. B27, 1450 (1983)

 

Transverse optic phonon T0 (k=0): 106 cm-1 (LST) or 109 cm-1

Longitude optic phonon L0 (k=0): 143 cm-1 (Hodby)

 

Gruneissen constant:

Ratio e*/e: 0.69

 

Photoelastic constants:

p11:

p12:

p44:

 

 

Band gap:

direct: 6.2 eV. at K

indirect: eV. at ° K

 

Plasmon energy: eV.

Exciton energy: 5.88 eV. (Ref.1)

Conduction band width: 1.1 eV.

 

Band structure discussed by:

 

Static dielectric constant: 4.94 or 4.68 (Hodby)

Optic dielectric constant: 2.69 or 2.68 (Hodby)

 

Electron mobility:

Hole mobility:

Polaron coupling constant: a = 2.51 or 2.55 ( for m*=1 ) (ambiguity)

Effective mass: conduction band: 0.325 or 0.335 (band mass)

valence band:

polaron mass: 0.536

 

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

0.5 eV.(Ref.2)

also: 1.0 eV. (Ref.3)

Jap.in estimates 1.2 eV. from colloids

3.18 eV. by Mott-Gurney (estimation) (Ref.6)

 

Spin-orbit coupling: 0.90 ( valence band) (Ref.4)

also: 1.10 eV. for exciton in iodides (Ref.5)

 

See also supplement of information on KI.

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References:

 

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

    2.  

  2. M.N. Pisanias & W.H. Hamill, Anomalous high-field electron injection & photoconduction in thin-film alkali halides, J. Appl. Phys. 51, 1569 (1980)

    3.  

  3. T. Sasaki, Y. Iguchi & H. Sugawara, Photoelectric emission of Potassium halides in the extreme ultraviolet, J. Phys .Soc. Jap. 30, 580 (1971)

    4.  

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

    5.  

  5. G. Guizetti, L. Nosenzo & E. Reguzzoni, Optical properties & electronic structure of alkali halides by thermoreflectivity, Phys. Rev. B15, 5921 (1977)

    6.  

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

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