金属镱低压吸氘研究

Study on Ytterbium Absorbing Deuterium at Low Pressure

在真空系统中的氘压低于 0 1MPa条件下研究了金属镱的吸氘性能 ,并对不同原子比的氘化物的物相进行了分析。在常压、3 0 0℃下 ,金属镱吸氘不明显 ;40 0℃时 ,金属镱经较长时间活化后吸附一定量的氘 ;5 0 0℃时 ,镱升华。 40 0℃时的吸氘实验结果表明 :从活化至开始吸氘直至吸附平衡需很长时间 ;氘 /镱原子比的高低与吸氘时间有关 ,饱和吸氘时的原子比最大为 2 0 0 ;金属镱为面心立方 (fcc)结构 ,a0 =0 .5 492nm。具有不同原子比的氘化镱的X射线衍射 (XRD)分析结果显示 :氘化镱有 2种结构 ,即面心立方结构 (a0 =0 .5 2 4nm)和正交结构 (a0 =0 .5 88nm、b0 =0 .3 5 8nm、c0 =0 .678nm ) ;金属镱吸氘后 ,立方结构氘化镱晶格常数及晶胞体积均发生收缩现象 ,收缩率分别约为 4%和 11%。正交结构氘化镱晶胞体积收缩约 14 %。

Properties of ytterbium absorbing deuterium at pressure less than 0.1 MPa in a vacuum system are studied and the phases of deuterides with various D/Yb atomic ratio are analyzed. Results indicate that there are two kinds of physical absorbed states of gases in Yb and its decomposed peaks present at 50～80 ℃ and 250 ℃, respectively. Yb will absorb deuterium when it exposes to deuterium at 400 ℃ for a long time and D/Yb atomic ratio is related with the exposed time and the most is YbH 2.00 . Yb has a fcc structure and a 0= 0.549 2 nm. Results of XRD analysis indicate that there are two kinds of structures in ytterbium deuterides, one is fcc with a 0=0.524 nm, another is orthorhombic structure and a 0=0.588 nm, b 0=0.358 nm, c 0=0.678 nm. Crystal cell parameter and volume of fcc Yb will contract when it absorbs deuterium, and contract ratio is 4% and 11%, respectively. Volume contract ratio of orthorhombic ytterbium deuteride is 14%.