We prepared GaN microcrystals for the source material of the sublimation method by the direct reaction of Ga-melt in NH3 ambient at temperatures of 850, 950 and 1050 °C. The typical size of the microcrystals is about 1-15 μm. The microcrystals have been investigated by solid 200 MHz nuclear magnetic resonance and micro-Raman scattering. Nuclear magnetic resonance powder spectra for 71Ga in the microcrystals were recorded near 50ppm. The disappearance of the relative broad peak in the spectra of the sample synthesized at 850 °C and the commercial GaN can be thought to come from the perturbed electric field gradient at 71Ga nuclei, which is induced by the internal stress due to native defects in the GaN microcrystals. Therefore, the GaN microcrystals synthesized at 1050 °C has the lower concentration of intrinsic defects, which is consistent with the experimental results from micro-Raman scattering measurements.
|Journal||Journal of the Korean Physical Society|
|Issue number||SUPPL. Part 1|
|Publication status||Published - 2001 Dec|
ASJC Scopus subject areas
- Physics and Astronomy(all)