____________________________________________________________________

_____________________________________________________________________

Strontium Oxide

Crystal: SrO

Structure: NaCl

_____________________________________________________________________

Mechanical and structural properties:

Cohesive energy:	eV
Lattice parameter:	2.57 Å
Density:	4.7 or 4.99 g/cm³

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

c₁₁: 16.55 (Ref.1), or 16.27 (Ref.2), or 17.76 (Ref.3)

c₁₂: 4.64 or 5.07 or 4.13

c₄₄: 5.26 or 6.4 or 5.95

P dependance for stiffness constants:

Z. Chang, E.K. Graham, Elastic properties of oxides in the NaCl-Structure, J. Phys. Chem. Sol. 38, 1355 (1977)

Compressibility (in 10¹¹ dynes/cm²): 0.116 ??

Poisson’s ratio: 0.21 (Voigt), or 0.39 (Reuss)

Debye temperature: 306 K

Melting temperature: 2430 or 2415 ° C

Phonon spectrum discussed by: Mon, Phys.Stat.Sol.33, 1068 (1969)

Also: Neutron Data:K.H. Rieder, R. Migoui and B. Renker, Lattice dynamics of Strontium Oxide, Phys. Rev. B12, 3374 (1975)

Transverse optic phonon T0 (k=0): 4.01*10exp13/sec., or 227 cm^-1 (Ref.4)

Longitude optic phonon L0 (k=0): 487 and 473 cm^-1 cited in Ref.4 (445 by LST)

Gruneissen constant:

Ratio e*/e:

Photoelastic constants:

p₁₁:

p₁₂:

p₄₄:

Electronic properties:

Band gap: direct: 6.7 eV. cited by Hendeson & Hughes, 5.45 eV cited by Bessent , 5.30 eV. (Ref.6)

First excitation: 5.81 eV. (Ref.6)

Valence band width: 9.2 eV. (?)

Excitons in BaO, SrO: (A.S. Rao, R.T. Keamey, Phys.Stat.Sol. 95, 243 (1979))

Includes such band data as Gamma Gap:

MgO	CaO	SrO	BaO
7.833	7,085	5.896	4.286 eV
26	34	74	120 meV

Band structure discussed by:

Static dielectric constant: 13.3, or 13.10±0.04 (Ref.7)

Optic dielectric constant: 3.31, or 3.46±0.04

Electron mobility: Hole mobility:

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

Effective mass: conduction band

valence band:

Electron affinity: (from bottom of conduction band under vacuum) ~0.5 eV (Ref.8)

Spin-orbit coupling: ( valence band)

Cation polarisation: 0.860 Å-1 Anion polarisation: 2.568 Å-1

_____________________________________________________________________

References:

1. Comptes Rendus B269, 30 (1969)

2. R.A. Bartels and R. Son CaO and SrO single crystal elastic constants and their pressure dependence, Bull. Am. Phys. Soc. 16, 357 (1971)

3. D.L. Johnson, H. Thrasher, R.J. Kearney, Elastic constants of SrO, J. Appl. Phys. 41, 427 (1970)

4. J.L. Jacobson and E.R. Nixon, Infrared dielectric response and lattice vibrations of Calcium and Strontium Oxides, J. Phys. Chem. Sol. 29, 967 (1968)

6. B. Ulrici, W. Ulrici, N.N. Kovalev, Optical absorption in SrO single crystals, Sov. Phys. Sol. St. 17, 2305 (1976)

7. J.L. Jacobson and E.R. Nixon, Infrared dielectric response and lattice vibrations of Calcium and Strontium Oxides, J.Phys.Chem.Sol. 29, 967 (1968)

8. S. 60, 13 (1948)

_____________________________________________________________________