Modeling the electronic structure and stability of three aluminum nitride phases

• J. Ruiz-González ^[2] ; G.H. Cocoletzi ^[2] ; L. Morales de la Garza ^[1]
  1. [1] Universidad Nacional Autónoma de México

     Universidad Nacional Autónoma de México

     México

     
  2. [2] Benemérita Universidad Autónoma de Puebla, México
• Localización: Revista Mexicana de Física, ISSN-e 0035-001X, Vol. 67, Nº. 3, 2021, págs. 343-350
• Idioma: inglés
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• Resumen

  • Phase transitions in aluminum nitride (AlN) were investigated by first-principles total energy calculations. Three AlN crystal structureswere considered: rock salt (NaCl), zinc blende, and wurtzite. The cohesion energy was calculated within both GGA and LDA formalisms.According to the cohesion energy results, the ground state corresponds to the hexagonal wurtzite phase, in agreement with experimentalevidence. However, the zinc blende and NaCl phases may be formed as metastable structures. To improve the energy gap calculated value,the modified Becke-Johnson pseudopotential was applied, with results showing good agreement with the experimental data. The ground-statestructure exhibits direct electronic transitions. However, the zinc blende and NaCl phases show an indirect bandgap. Provided that externalpressures may induce transitions from wurtzite to zinc blende or rock salt, these transitions were also investigated. Estimation of the pressureat the phase transition indicates that small pressures are needed to achieve such transitions.