First principles phase diagram calculations for the wurtzite-structure quasibinary systems SiC-AlN, SiC-GaN and SiC-InN
- Creators
- Burton, B. P.
- Demers, Steve
- van de Walle, A.
Abstract
The cluster-expansion method was used to perform first principles phase diagram calculations for the wurtzite-structure quasibinary systems (SiC)_(1-X)(AlN)_X, (SiC)_(1-X) (GaN)_X and (SiC)_(1-X)(InN)_X; and to model variations of band gaps as functions of bulk compositions and temperature. In SiC-AlN, plane wave pseudopotential formation-energy calculations predict low-energy metastable states with formation energies, ΔE_f ≾ 0.004 eV/mole (mol = one cation + one anion). The crystal structures of these states are all of the form (SiC)_m(AlN)_n(SiC)_o(AlN)_p…(m,n,o,p integers), where (SiC)_m indicates m SiC-diatomic-layers ⊥ to the hexagonal c-axis (c_(Hex)) and similarly for (AlN)_n, (SiC)_o and (AlN)_p. The presence of low-energy layer-structure metastable states helps to explain why one can synthesize (SiC)_(1-X)(AlN)_X films, or single crystals with any value of X, in spite of the apparently strong tendency toward immiscibility. In SiC-GaN, ordered structures are predicted at X = 1/4, 1/2, and 3/ 4 (Pm, Pmn2_1 and Pm, respectively). In SiC-InN, one Cmc2_1 ordered phase is predicted at X = 1/2.
Additional Information
© 2011 American Institute of Physics. Received 2 November 2010; accepted 17 May 2011; published online 20 July 2011. This work is supported by NIST, the Department of Energy National Nuclear Security Administration under Award No. DE-FC52-08NA28613, the National Science Foundation under Grant No. DMR-0907669, and through TeraGrid resources at TACC under Grant No. TG-DMR050013N.Attached Files
Published - Burton2011p15812J_Appl_Phys.pdf
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Additional details
- Eprint ID
- 25372
- Resolver ID
- CaltechAUTHORS:20110920-140207792
- NIST
- DE-FC52-08NA28613
- Department of Energy National Nuclear Security Administration
- DMR-0907669
- NSF
- TG-DMR050013N
- TeraGrid resources at TACC
- Created
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2011-09-20Created from EPrint's datestamp field
- Updated
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2023-01-19Created from EPrint's last_modified field