【摘要】 在二元系统Nb₂O₃-Al₂O₃中,用熔剂法在1300℃于弱还原气氛下合成了新化合物Al₃Nb₅O₁₆,并获得了其粉晶X射线衍射谱,单晶结构测定获得其结构参数如下:M_r=801.476,单斜晶系,空间群C2/m,α=12.172（6）（?）,b=3.740（1）（?）,c=6.486（2）（?）,β=107.67（3）⁰,V=281.3（4）（?）,z=1,D_m=4.74g/cm³,D₀=4.73g/cm³,F（000）=372,μ（M_οK_α）=48.52cm^-1。对于424个Ⅰ≥15σ（Ⅰ）的衍射点,最终结构偏离因子R=0.023,R_w=0.032。该结构由铌氧八面体[NbO₆]和铝氧八面体[AlO₆]共边或共点组成,Nb原子及Al原子填充于氧八面体的中心空隙,但Al原子占据的等效点系存在部分Nb原子,该化合物中存在Nb⁴⁺与Nb⁵⁺的混合。更多还原

【Abstract】 In the binary system Nb₂O₅-Al₂O₃, a new compound Al₃Nb₅O₁₆ was sythesized by the flux method at 1300℃ in the weak reducing atmosphere, and its X-ray powder pattern data were obtained. Crystal data from single-crystal are as follows: α=12.172（6）（?） b=3.740（1）（?）, c=6.486（2）（?）, β=107.67（3）°, V=281.3（4）（?）³Z=1, D_m=4.74g/cm³, D_c=4.73g/cm³, F（000）=372, μ（MoKa）=48.52cm^-1. For 424 unique refractions with an intensity greater than 15σ（Ⅰ）, the final agreement factors are R=0.023, R_w=0.032. The structure may be consisted of edge-shared and comer-shared NbO₆ and AlO₆ octahedra, the atoms Nb and Al are located at the vacants of the octahedra, but a fraction orAl in the lattice are replaced by Nb atoms, there are Nb⁵⁺ and Nb⁴⁺ in the compound.更多还原