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silicon carbide


Gas phase thermochemistry data

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Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Quantity Value Units Method Reference Comment
Deltafgas719.65kJ/molReviewChase, 1998Data last reviewed in March, 1966
Quantity Value Units Method Reference Comment
gas,1 bar213.02J/mol*KReviewChase, 1998Data last reviewed in March, 1966

Gas Phase Heat Capacity (Shomate Equation)

Cp° = A + B*t + C*t2 + D*t3 + E/t2
H° − H°298.15= A*t + B*t2/2 + C*t3/3 + D*t4/4 − E/t + F − H
S° = A*ln(t) + B*t + C*t2/2 + D*t3/3 − E/(2*t2) + G
    Cp = heat capacity (J/mol*K)
    H° = standard enthalpy (kJ/mol)
    S° = standard entropy (J/mol*K)
    t = temperature (K) / 1000.

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Temperature (K) 298. - 1000.1000. - 6000.
A 60.3218033.36570
B 4.4239404.437140
C -61.79470-0.865113
D 39.061400.057726
E -1.6759913.073291
F 696.3070717.4580
G 277.6700262.5750
H 719.6480719.6480
ReferenceChase, 1998Chase, 1998
Comment Data last reviewed in March, 1966 Data last reviewed in March, 1966

Condensed phase thermochemistry data

Go To: Top, Gas phase thermochemistry data, Constants of diatomic molecules, References, Notes

Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Quantity Value Units Method Reference Comment
Deltafsolid-71.55kJ/molReviewChase, 1998«alpha» phase; Data last reviewed in March, 1966

Solid Phase Heat Capacity (Shomate Equation)

Cp° = A + B*t + C*t2 + D*t3 + E/t2
H° − H°298.15= A*t + B*t2/2 + C*t3/3 + D*t4/4 − E/t + F − H
S° = A*ln(t) + B*t + C*t2/2 + D*t3/3 − E/(2*t2) + G
    Cp = heat capacity (J/mol*K)
    H° = standard enthalpy (kJ/mol)
    S° = standard entropy (J/mol*K)
    t = temperature (K) / 1000.

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Temperature (K) 298. - 1000.1000. - 4000.298. - 1100.1100. - 4000.
A 20.5585946.9022220.5000948.22227
B 64.579625.84596863.371705.004148
C -52.98827-1.085410-49.54023-1.037594
D 16.958130.09302114.828010.086339
E -0.781847-3.448876-0.759969-3.912333
F -82.73693-95.46716-84.29337-98.46542
G 19.9084856.9752020.3092657.76221
H -71.54598-71.54598-73.22000-73.22000
ReferenceChase, 1998Chase, 1998Chase, 1998Chase, 1998
Comment «alpha» phase; Data last reviewed in March, 1966 «alpha» phase; Data last reviewed in March, 1966 «beta» phase; Data last reviewed in March, 1966 «beta» phase; Data last reviewed in March, 1966

Constants of diatomic molecules

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, References, Notes

Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Data compiled by: Klaus P. Huber and Gerhard H. Herzberg

Data collected through August, 1977

Symbols used in the table of constants
SymbolMeaning
State electronic state and / or symmetry symbol
Te minimum electronic energy (cm-1)
ωe vibrational constant – first term (cm-1)
ωexe vibrational constant – second term (cm-1)
ωeye vibrational constant – third term (cm-1)
Be rotational constant in equilibrium position (cm-1)
αe rotational constant – first term (cm-1)
γe rotation-vibration interaction constant (cm-1)
De centrifugal distortion constant (cm-1)
βe rotational constant – first term, centrifugal force (cm-1)
re internuclear distance (Å)
Trans. observed transition(s) corresponding to electronic state
ν00 position of 0-0 band (units noted in table)
Diatomic constants for 28Si12C
StateTeomegaeomegaexeomegaeyeBealphaegammaeDebetaereTrans.nu00
No spectra have been conclusively assigned to SiC. The following constants are from ab initio calculations Lutz and Ryan, 1974:
a 1Sigma+ (6628) (1018)   (0.695)     (1.70)  
* 3Sigma- (5597) (606)   (0.556)     (1.90)  
* 3Pii 0 1 (983)   (0.606)     (1.82) 1  

Notes

1 Lovas, 1974 assumes a 1Sigma ground state and estimates re = 1.65 from an extrapolation to SiC of the shortening of Si-O, Si-N single bonds in the corresponding diatomic molecules.
2Thermochemical value (mass-spectrometry) Verhaegen, Stafford, et al., 1964.

References

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Constants of diatomic molecules, Notes

Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Chase, 1998
Chase, M.W., Jr., NIST-JANAF Themochemical Tables, Fourth Edition, J. Phys. Chem. Ref. Data, Monograph 9, 1998, 1-1951. [all data]

Lutz and Ryan, 1974
Lutz, B.L.; Ryan, J.A., Silicon carbide: its ground state and predicted spectrum, Astrophys. J., 1974, 194, 753. [all data]

Lovas, 1974
Lovas, F.J., Small silicon molecules: possible sources of the unidentified molecular lines U81.5, U86.2, U89.2, and U90.7, Astrophys. J., 1974, 193, 265. [all data]

Verhaegen, Stafford, et al., 1964
Verhaegen, G.; Stafford, F.E.; Drowart, J., Mass spectrometric study of the systems boron-carbon and boron-carbon-silicon, J. Chem. Phys., 1964, 40, 1622. [all data]


Notes

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