高压固相复分解(HPSSM)反应法是一种新型的金属氮化物合成方法.本文对HPSSM法合成的GaN晶体进行了高压、高温和低温原位拉曼散射研究.给出了HPSSM GaN各拉曼振动模的Grüneisen参数以及一阶拉曼频移和拉曼模半峰宽随温度变化的关系.通过SCM空间相关模型对常温常压下GaN晶体拉曼光谱拟合,得到其空间关联长度;并利用三声子耦合模型拟合变温拉曼光谱.实验所获得的物理参数同MOCVD GaN的参数进行了比较.

High-pressure solid-state metathesis (HPSSM)reaction is a novel route to synthesis metal nitride.GaN synthesized by HPSSM was investigated by high-pressure,high-temperature,and low-temperature Raman spectroscopy.Grüneisen parameters for each Raman mode of GaN were determined and Raman shift and Raman line width dependence on temperature was analyzed.Ambient Raman spectra of GaN was fitted by Spatial Correlation Model (SCM)and the Correlation Length was obtained;Three-phonon Coupling Model and Four-phonon Coupling Model were used to analyze Raman spectra of GaN from 77 K to 873 K.The obtained experimental data were compared with that of MOCVD GaN.