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Potassium Chloride

Crystal: KCl

Structure: NaCl

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Lattice formation energy:

-7.19 eV.

Lattice parameter:

3.14 Å (3.116 at 0K.)

Density:

2.038 or 1.98 g/cm3

 

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

 

c11: 3.98 or 4.832

c12: 0.62 or 0.54

c44: 0.625 or 0.663

 

Compressibility (in 1011 dynes/cm2): 0.574 ??

Poisson ratio: 0.2494 (Voigt)

 

Debye temperature: 235 K

Melting temperature: K

 

Phonon spectrum discussed by:

G. Raunio & S. Rolandson, Lattice dynamics of NaCl, KCl, RbCl & RbF, Phys.Rev. B2, 2098 (1970)

 

Transverse optic phonon T0 (k=0): 142 or 151 cm-1

Longitude optic phonon L0 (k=0): 212 cm-1 (Hodby) which means: 3.99*1013 rad/sec.

 

Gruneissen constant:

Ratio e*/e: 0.80

 

Photoelastic constants:

p11:

p12:

p44:

 

 

Band gap:

direct: 6.4 eV. at K

indirect: eV. at ° K

 

Plasmon energy: 14.2 eV. (Ref.1)

Exciton energy: 8.6 eV. or 7.79 eV. (Ref.2)

Conduction band width: 0.6 eV.

 

Electronic band structure of the alkali halides. II:Critical survey of theorical calculation, R.T. Poole, J. Liesegang, R.C.G. Leckey & J.G. Jenkin, Phys. Rev. B11, 5194 (1975)

which gives:

Valence band width:

2.7 eV.

Gap:

8.4 eV.

Electron affinity:

0.5 eV.

 

Band structure discussed by:

N.O. Lipari & A.B. Kunz, Energy bands for KCl, Phys.Rev. B4, 4639 (1971)

Summary of band theory:

Mixed approach of linear-combination-of-atomic-orbitals & orthogonalized-plane-wave methods to the band-structure calculation of alkali-halide crystals, S.M. Mujibur Rahman, A.M. Harun Ar Rashid & S.M. Chowdhury, Phys. Rev. B14, 2618 (1976)

 

Static dielectric constant: 4.68 or 4.49 (Hodby)

Optic dielectric constant: 2.13 or 2.20 (Hodby)

 

Other information for T, P dependence:

Pressure & temperature dependence of the static dielectric constants of KCl, LiF & MgO, R.A. Bartells & A. Smith, Phys.Rev. B7, 3885 (1973)

 

Electron mobility:

Hole mobility:

Polaron coupling constant:

a = 5.8 ( for m*= -1 )

a = 3.97 for true m*

or a = 3.46 or 3.60 (Hodby)

 

Effective mass:

conduction band: 0.496 (band mass)

valence band: 0.432 or 0.467 (Hodby) 0.922 for a polaron

 

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

0.6 (Ref.3 & 4)

Mott-Gurney estimate 3.78 (Ref.7)

Japin estimates 0.23 eV. from colloids

Spin-orbit coupling:

0.11 ( valence band) (Ref.5)

0.13 (excitons in chloride) (Ref.6)

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Other information:

 

S. Hart, J.of Phys. D10, Letter261 (1977)

 

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References:

 

  1. Journal de Physique et le Radium, 28 (1981)

    2.  

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

    3.  

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

    4.  

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

    5.  

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

    6.  

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

    7.  

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

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