____________________________________________________________________

_____________________________________________________________________

Manganese Oxide

Crystal: MnO

Structure:

_____________________________________________________________________

Mechanical and structural properties:

MnO, Mn₂O₃ and Mn₃O₄ are insulators. MnO₂ is (nearly) a semiconductor

Cohesive energy:	eV
Lattice parameter:	2.20 Å
Density:	5.39 g/cm³ (Ref.1)

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

c₁₁: 22.30 (Ref.2)

c₁₂: 12.00

c₄₄: 7.90

Compressibility (in 10¹¹ dynes/cm²): 0.0647 ??

Poisson ratio:

Debye temperature: 436 K

Melting temperature: 1650 ° C (or 1780)

Neel temperature: 122 K

Phonon spectrum discussed by:

K.S. Upadhyaya and R.K. Singh, Shell model lattice dynamics of transition metal-oxides, J.Phys.Chem.Sol. 35, 1175 (1974)

Transverse optic phonon T0 (k=0): 268 cm^-1 (Ref.3)

Longitude optic phonon L0 (k=0): 495 cm^-1

K=0 magon: 27.7 cm^-1 (Ref.3)

Curves: see Ref.3, 3935

Gruneissen constant:

Ratio e*/e:

Photoelastic constants:

p₁₁:

p₁₂:

p₄₄:

MnO elastic constants at 4.2-300K.:

S.B. Palmer, A. Waintal

The temperature dependence of the elastic constants of MnO

Sol.St.Com. 34, 663 (1980)

Electronic properties:

Band gap:

direct: 2.8 eV.

indirect: eV.

Gap: eV.

First exciton: eV.

Band structure discussed by:

Static dielectric constant: 12.8-18.0

Optic dielectric constant: 4.95

m = 2.16

e (¥ )= 4.66 (Winchell & Winchell)

MnO: relation of A, B, C band positions to dielectric anomaly:

M.S. Seehra and R.D. Groves, Blue shifts of the optical transitions in MnO below TN, J. Phys. C16, Letter 411 (1983)

X-ray Kbeta spectra of Mn oxides:

K. Tsutsimi, H. Nakamori, K. Ichikawa, X-ray Mn Kbeta emission spectra of manganese oxides and manganates, Phys. Rev. B13, 929 (1976)

Electron mobility:

Hole mobility:

Polaron coupling constant: a = 2.09 ( for m*=1 )

Effective mass:

conduction band:

valence band:

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

Spin-orbit coupling: ( valence band)

Cation polarisation: Å^-3

Anion polarisation: Å^-3

_____________________________________________________________________

Other information:

See supplementary information on MnO, below.

_____________________________________________________________________

References:

1. D.W. Oliver, The elastic moduli of MnO, J. Appl. Phys. 40, 893 (1969)

2. A.N. Grishmanovski, Singularities of the elastic properties of MnO in the vinicity of a phase transition, Sov. Phys. Sol. St. 18, 838 (1976)

3. H.H. Chou, H.Y. Fan, Light scattering by magnons in CoO, MnO, and alpha-MnS, Phys. Rev. B13, 3934 (1976)

_____________________________________________________________________

Supplementary information for MnO

Principal magnetic susceptibilities of MnO and their temperature dependence.

M.S. Jagadeesh and M.S. Seehra Phys.Rev. B23, 1185 (1981)

The temperature dependence of the principal susceptibilities, c // and c ^ , of MnO are reported in the range of 4.2 to 300K. from the studies in a single crystal from which nonstoichiometric have been removed. A procedure combining selective stress applied along [111] during measurements (to remove T domains), field dependence of the magnetisation (to remove S domains), and the measurement of the initial c is used to determine both c // and c ^ below T(N) (117.9K). A stress £ 25 bars is sufficient to remove T domains and a critical field Hc@ 2 kOe is determined from the field dependence of the magnetisation for the vector H//(111) plane. Comparison of the temperature dependence of c ^ in MnO vis-à-vis MnF2 ad RbMnF3 is made, and it is suggested that the observed differences may at least be partly due to the lattice distortion effects in MnO below T(N). For c // in MnO, the data fit T² variation to about T(N)/3. Further theoretical work is necessary to explain all the observations in MnO.

_____________________________________________________________________