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Rubidium Bromide

 

Crystal: RbBr

Structure: NaCl

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Lattice formation energy:

-6.62 eV

Lattice parameter:

3.42 Å (3.410 at 0K.)

Density:

3.35 g/cm3

 

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

 

c11: 3.17 (Ref.1) or 3.863

c12: 0.42 or 0.474

c44: 0.39 or 0.4085

 

Compressibility (in 1011 dynes/cm2): 0.75 ??

Poisson ratio:

Debye temperature: 136 K

Melting temperature: K

 

Phonon spectrum discussed by:

S. Rolandson & G. Raunio, Lattice dynamics of RbBr, J. Phys. C4, 958 (1971)

 

Transverse optic phonon T0 (k=0): 94.5 cm-1 or 1.65*1013/sec.

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

 

Gruneissen constant:

Ratio e*/e: 0.82

 

Photoelastic constants:

p11:

p12:

p44:

 

 

Band gap:

direct: eV. at K

indirect: eV. at ° K

 

Plasmon energy: eV.

Exciton energy: 6.64 eV. (Ref.2)

 

Band structure:

Ultraviolet electron spectra of Rubidium halides, C.S. Inouye & W. Pong, Phys.Rev. B15, 2265 (1977)

 

Static dielectric constant: 5.0 or 4.51

Optic dielectric constant: 2.33 or 2.36

 

Electron mobility:

Hole mobility:

Polaron coupling constant: a = 6.6 ( for m*=1 )

 

Effective mass:

conduction band:

valence band:

 

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

+0.67 (Ref.3)

3.56 (Ref.4) (estimation)

 

Spin-orbit coupling: 0.48 ( valence band) (Ref.5)

 

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References:

 

  1. M. Ghafelehbashi, D. Dankedar & A.L. Ruoff, Pressure & temperature dependence of the elastic constants of RbCl, RbBr & RbI, J. Appl. Phys. 41, 652 (1970)

    2.  

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

    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. N.F. Mott & R.W. Gurney, "Electronic processes in Ionic crystals"

    5.  

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

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