【摘要】 本文用扩展X射线吸收谱（EXAFS）和X射线大角散射谱（WAXS）对远红外光纤材料复合卤化物玻璃（MnF₂）_x（BaCl₂）_166-x（x=65,60,55）的短程结构进行了研究。从MnK吸收限的EXAFS和样品的非晶衍射图,得到了Mn原子的近邻原子配位信息。结果表明F,Cl原子在Mn原子周围形成了混合配位的八面体（MnCl₂F₄）,这些八面体以Mn—F键为桥键连成“之”字型链,Ba分布于各链之间将它们连结起来。随着BaCl₂含量从35%mol增加到45%mol,“之”字型链发生断裂,形成孤立的八面体（MnCl₂F₄）。更多还原

【Abstract】 A short range structure investigation of halide glasses （MnF₂）x（BaCl₂）_100-x（x = 65, 60, 55） has been made using the extended X-ray absorption fine structure （EXAFS） and the wide angle X-ray scattering （WAXS） techniques. The local structure information around the Mn is derived from the study of the MnK absorption edge EXAFS and the X-ray scattering intensity of the materials, respectively. The results show that the F and Cl atoms in the first neighbour shell of the Mn atom construct a octahedra （MnCl₂F₄） with the bond-length r_Mn-Cl = 0.246 nm and r_Mn-F= 0.200 nm in the glass of x = 65, which share the atom F with the neighbouring one to form zigzag chains linked by Ba atoms distributed between them. With decreasing of the amount of MnF2 below x = 65, the bond-length r_Mn-Cl and the Debye-Waller factor σ_Mn-Cl² of Mn-Cl increase, and that of Mn-F is almost invariant. The disappearance of the Mn-Mn peak has been found from x = 60 to x = 55 with an abrupt increase in σ_Mn-Cl and s_Mn-Cl², which can be explained as the chains being broken to form the solitude octahc-dra （MnCl₂F4）.更多还原