Low-temperature phase separation in GaN nanowires: An in situ x-ray investigation

In this study, we in situ employed low-temperature x-ray diffraction to investigate phase separation in GaN nanowires. Our observations showed that a distinct phase separation developed below 260K, the zinc-blende phase, which is related to short range ordering. The correlation lengths of the zinc-blende phase reached their maximum at 140K but correlation length was still revealed at around 23nm. Our results may be understood using the finite size model and support the conclusion that the phase separation was reversible and occurred through the interaction of the characteristic size of the ordered domain of the GaN nanowires.