Synthesis, Raman scattering, and infrared spectra of a new condensed form of GaN nanophase material

A new form of transparent condensed nanophase material of GaN was synthesized directly by ammono-thermal synthetic route. Nano-sized effects and thermal stability of that material were investigated through Raman scattering and infrared spectra. Compared with bulk GaN, we observed the Raman low-energy-shift of the phonon frequency of E-2(high) and the transverse optical mode [E-1(TO)], the infrared high-energy-shift of omega(T), and the variation of relative intensity I-E2/E1(TO). These characteristics can be attributed to the existence Of the interface effects and the vacancy of N in the GaN nanophase material. This material has a high thermal stability even at 900 degrees C as indicated through infrared and Raman spectral investigation of annealed samples of as-synthesized nanophase material.