Hexagonal-to-Cubic Phase Transformation in GaN Nanowires by   Ga+-Implantation
  Hexagonal to cubic phase transformation is studied in focused ion beam assisted Ga+-implanted GaN nanowires. Optical photoluminescence and cathodoluminescence studies along with high-resolution transmission electron microscopic structural studies are performed to confirm the phase transformation. In one possibility, sufficient accumulation of Ga from the implanted source might have reduced the surface energy and simultaneously stabilized the cubic phase. Other potential reason may be that the fluctuations in the short-range order induced by enhanced dynamic annealing (defect annihilation) with the irradiation process stabilize the cubic phase and cause the phase transformation. 
Sandip Dhara, Anindya Datta, Chi-We Hsu, Chien-Ting Wu, Ching-Hsing   Shen, Zon-Huang Lan, Kuei-Hsien Chen, Li-Chyong Chen, ...