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Potassium Fluoride

 

Crystal: KF

Structure: NaCl

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Lattice formation energy:

-8.24 eV

Lattice parameter:

2.66 Å (2.648 at 0K.)

Density:

g/cm3

 

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

 

c11: 7.570 (7.585 at 4K.) (Ref.1)

c12: 1.35 (1.473 at 4K.)

c44: 1.336 (1.293 at 4K.)

 

Compressibility (in 1011 dynes/cm2): 0.292 ??

Poisson ratio:

 

Debye temperature: 327 or 335 K

Melting temperature: K

 

Phonon spectrum discussed by:

W. Burher, Lattice dynamics of Potassium Fluoride Phys. Stat. Sol. 41, 789 (1970)

 

Transverse optic phonon T0 (k=0): 190 or 201.5 cm-1

Longitudinal 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: 17.5 eV. (Ref.2)

Exciton energy:

10.6 eV. (Ref.2)

9.58 eV. (Ref.3)

 

Valence band width: 3.70 eV.

 

Band structure discussed by:

 

Static dielectric constant: 6.05 or 5.11

Optic dielectric constant: 1.85 or 1.86

 

Electron mobility:

Hole mobility:

Polaron coupling constant: a = 5.8 ( for m*=1 )

 

Effective mass:

conduction band:

valence band:

 

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

0.1 (Ref.3)

4.14, by Mott-Gurney (Ref.4)

 

Spin-orbit coupling: ( valence band)

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References:

 

1. Physics Abstracts, 71, No.2056

 

2. Journal de physique et le Radium, 28 (1981)

 

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

 

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

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