利用 XAFS( X-射线吸收精细结构 )方法研究六方的纳米晶和晶体 Ga N在 78K和 3 0 0 K温度下 Ga原子的局域配位环境结构 .对于第一近邻 Ga-N配位 ,纳米晶 Ga N的平均键长 R、配位数 N、热无序度σT 和结构无序度σS与晶体 Ga N的相近 ,分别为 0 .194 nm、4 .0、0 .0 0 52 nm、0 .0 0 0 7nm ;当温度从 78K增加到 30 0 K,Ga N样品中 Ga-N配位的 σT 增加不多 ,小于 0 .0 0 0 5nm,表明第一近邻 Ga-N配位的共价键作用力较强 ,几乎不受温度和晶体状态的影响 .对于第二近邻 Ga-Ga配位 ,R为 0 .318nm,纳米晶 Ga N的σS( 0 .0 0 57nm )比晶体 Ga N的 ( 0 .0 0 1nm)大 0 .0 0 4 7nm;在78K和 30 0 K时 ,纳米晶 Ga N样品的 Ga-Ga配位的σT 分别为 0 .0 0 53nm和 0 .0 0 85nm,这一结果表明 Ga-Ga配位的σT受温度变化产生很大影响 .纳米晶 Ga N中 Ga原子的局域配位环境与晶体 Ga N的差别主要表现在第二近邻 Ga-Ga配位的 σS相对较大 ,可能是由于纳米晶 Ga N内部缺陷及存在较多的表现不饱和配位原子所致 XAFS (X-ray absorption fine structure) method was used to study the local coordination structure of Ga atoms between hexagonal nanocrystals and crystalline GaN at 78K and 3000 K. For the first neighbor Ga-N coordination, The average bond length R, the coordination number N, the degree of thermal disorder σT and the degree of structural disorder σS of the crystalline Ga N are close to those of the crystalline Ga N, which are respectively 0,194 nm, 4.0,0,0,052 nm, 0 0 0 0 7 nm. When the temperature is increased from 78 K to 30 0 K, the σT of Ga-N coordination in Ga N sample increases little, less than 0.00005 nm, indicating that the first neighbor Ga-N coordination The covalent bond force is strong, almost independent of the temperature and the crystal state.For the second neighbor Ga-Ga coordination, R is0.318nm, the nanocrystalline GaN σS (0.057nm) is more stable than the crystalline Ga (0. 0 0 1nm) was 0. 0 0 4 7nm. At 78K and 30 0 K, the σT of Ga-Ga coordination of nanocrystalline Ga N samples was respectively 0.00505 nm and 0.0000 85nm.The results show that the σT of Ga-Ga coordination has a great influence on the temperature change.The difference between the local coordination environment of Ga atoms and Ga N in nanocrystalline GaN is mainly shown in the second nearest neighbor Ga-Ga Bit sigma is relatively large, probably due to satisfied Crystal Ga N and the presence of internal defects more performance due to coordinatively unsaturated atoms