Manganese 3×3 and √3×√3-R30 â̂̃ structures and structural phase transition on w-GaN(0001̄) studied by scanning tunneling microscopy and first-principles theory
Manganese deposited on the N-polar face of wurtzite gallium nitride [GaN (0001̄)] results in two unique surface reconstructions, depending on the deposition temperature. At lower temperature (less than 105 â̂̃C), it is found that a metastable 3×3 structure forms. Mild annealing of this Mn 3×3 struct...
| Autores: | , , , , , , , , , |
|---|---|
| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2013 |
| País: | Argentina |
| Institución: | Consejo Nacional de Investigaciones Científicas y Técnicas |
| Repositorio: | CONICET Digital (CONICET) |
| Idioma: | inglés |
| OAI Identifier: | oai:ri.conicet.gov.ar:11336/77841 |
| Acceso en línea: | http://hdl.handle.net/11336/77841 |
| Access Level: | acceso abierto |
| Palabra clave: | Gallium Nitride Spintronics Stm Ab Initio Calculations https://purl.org/becyt/ford/1.3 https://purl.org/becyt/ford/1 |
| Sumario: | Manganese deposited on the N-polar face of wurtzite gallium nitride [GaN (0001̄)] results in two unique surface reconstructions, depending on the deposition temperature. At lower temperature (less than 105 â̂̃C), it is found that a metastable 3×3 structure forms. Mild annealing of this Mn 3×3 structure leads to an irreversible phase transition to a different, much more stable √3×√3-R30â̂̃ structure which can withstand high-temperature annealing. Scanning tunneling microscopy (STM) and reflection high-energy electron diffraction data are compared with results from first-principles theoretical calculations. Theory finds a lowest-energy model for the 3×3 structure consisting of Mn trimers bonded to the Ga adlayer atoms but not with N atoms. The lowest-energy model for the more stable √3×√3-R30â̂̃ structure involves Mn atoms substituting for Ga within the Ga adlayer and thus bonding with N atoms. Tersoff-Hamman simulations of the resulting lowest-energy structural models are found to be in very good agreement with the experimental STM images. |
|---|