(Color online) Representations of some (001) w layer structures with X = 1/2: (a) the simplest (SiC)1(AlN)1 1:1-supercell which is predicted to be the lowest energy configuration at X = 1/2 [viewed with (001) w almost in the plane of the page. (b) (SiC)2(AlN)2 2:2-supercell; (c) (SiC)2(AlN)2(SiC)1(AlN)1 2:1:1:2-supercell; and (d) (SiC)3(AlN)2(SiC)1(AlN)2 3:2:1:2-supercell (online, black = Si; blue = Al; green = C; red = N).
(Color online) Calculated, VASP, formation energies, , for the SiC-AlN quasibinary (solid circles, black online). The for (SiC) m (AlN) n …layer structures (layers ) are indicated by open squares (green online): (a) The full set of 177 ; (b) the low energy part of the distribution. Note the unusual distribution of formation energies: low- metastable states. Note the unusual distribution of formation energies: low- metastable states; a relatively depopulated gap; and a very wide range of high-energy configurations, 0.10 eV/mol 0.65 eV/mol.
(Color online) Cluster expansion based GS analyses for unweighted- (open square, red online), and weighted- (plus signs, blue online) fits; VASP values are indicated by solid circles (black online).
(Color online) Cluster expansions of band gaps based on hybrid-functional bandgap calculations: (a) SiC-AlN; (b) SiC-GaN; (c) --InN, only the InN-rich half of this system was modeled because the broad miscibility gap on the SiC-rich side extends to such high-T.
(Color online) VASP and corresponding CE values for in SiC-GaN (color online: = solid black circles; = open red squares; dashed lines indicate convex hulls): (a) the energy distribution in SiC-GaN is similar to that in SiC-AlN, i.e., a wide -range; but unlike SiC-AlN, (b) the SiC-GaN distribution includes many , which indicates the presence of ordered phases.
(Color online) Predicted GS structures for: (a) and , (b) SiGaCN, and (c) SiInCN (online, black = Si, green = C; red = N; gold = Ga; violet = In online). Projections are close to the pseudohexagonal c-axis to emphasize differences in ordering within: (1) the (001) w mixed-double-layers; and (2) ordering in cation-anion-cation. columns along . In and , mixed (001) w -layers alternate with SiC- and GaN-double-layers, respectively.
(Color online) VASP and corresponding CE values for in SiC-InN (color online: = solid black circles; = open red squares; dashed lines indicate convex hulls): (a) the energy distribution in SiC-GaN is similar to that in and SiC-GaN, but more compact with only three 0.
(Color online) Comparison of experimental data from Zangvil and Ruh10 with the results of first principles based calculations with a weighted-fit cluster expansion (shown in blue online).
Calculated phase diagram for the system SiC-GaN.
Calculated phase diagram for the system SiC-InN.
Crystal structure parameters for the observed (wurtzite) and (fully relaxed) predicted phases in the SiC-AlN, SiC-GaN and SiC-InN quasibinary systems. The unit cells of predicted X = 1/4, X = 1/2 and X = 3/4 phases are all supercells of wurtzite. Cell constants are given in and degrees; and all experimental values are from Pearson’s Handbook.26
Article metrics loading...
Full text loading...