氮化铝镓纳米固体材料的合成及其拉曼光谱

SYNTHESIS OF Al_xGa_(1-x) N ALLOY NANOCRYSTALLINE SOLIDS AND THEIR RAMAN SCATTERING SPECTRA

利用氨热法合成了AlxGa1 -xN合金的纳米固体 ,其中Al含量的摩尔数可在x =0～ 1的范围内变化 .在x值从 0到 1整个范围内 ,对该合金的纳米固体进行了激光Raman光谱分析 ,证实了A1 (LO)声子的单模式行为和E2 声子的双模式行为 .从实验现象中还可以推断出A1(TO)声子可能具有单模式行为 .Al(LO)声子频率在x =0～ 0 .5范围内迅速单调增加 ,当x >0 .5时则缓慢增加 ,这可能是由于纳米颗粒之间的相互作用造成的 .对于A1 (TO) ,A1 (LO) ,和E2 (GaN)声子模式 ,其线宽在x =0 .

Al x Ga 1- x N alloy nanocrystalline solids were synthesized by ammonothermal method. The Al compositional fraction x in the materials ranged from 0-1. The Raman scattering spectra of the alloy within the whole range of x values were investigated, from which a one_mode type behavior of A 1(LO) phonon and a two_mode type behavior of E 2 phonon were clearly demonstrated. It can be further deduced from the observed results that the A 1(TO) phonon may have a one-mode type behavior. The measured frequencies of A l(LO) phonon showed a rapid monotonous increase with increasing of x from 0 to 0.5. A slow increase of the frequencies after x >0.5 was observed, which might be resulted from the interaction among the nanoparticles in the condensed solids. For A 1(TO), A 1(LO) and E 2(GaN) phonon modes, the linewidth behaviors followed a pattern that exhibited a maximum at x =0.5, a value at which a maximum disorder should be expected in a random system.