First principles phase diagram calculations for the wurtzite-structure systems AlN–GaN, GaN–InN, and AlN–InN

B. P. Burton, A. van de Walle, U. Kattner
2006 Journal of Applied Physics  
First principles phase diagram calculations were performed for the wurtzite-structure quasibinary systems AlN-GaN, GaN-InN, and AlN-InN. Cluster expansion Hamiltonians that excluded, and included, excess vibrational contributions to the free energy, F vib , were evaluated. Miscibility gaps are predicted for all three quasibinaries, with consolute points, ͑X C , T C ͒, for AlN-GaN, GaN-InN, and AlN-InN equal to ͑0.50, 305 K͒, ͑0.50, 1850 K͒, and ͑0.50, 2830 K͒ without F vib , and ͑0.40, 247 K͒,
more » ... 0.50, 1620 K͒, and ͑0.50, 2600 K͒ with F vib , respectively. In spite of the very different ionic radii of Al, Ga, and In, the GaN-InN and AlN-GaN diagrams are predicted to be approximately symmetric.
doi:10.1063/1.2372309 fatcat:56jf4jzi2vb5hozm3js4o7jeem