Mo对A_2B_7型La-Mg-Ni贮氢电极合金相结构及电化学性能的影响

Influence of Mo on Microstructure and Electrochemical Properties of A_2B_7-type La-Mg-Ni Hydrogen Storage Electrode Alloy

采用磁控溅射技术在石英衬底上制备出(Ge/SiO2)15多层膜,并在不同温度下对其进行退火处理。XRD和Raman结果表明:溅射态的薄膜为非晶态,当退火温度为500℃时开始出现明显的结晶衍射峰,随后晶化率明显增大,当600℃后,薄膜的晶化率几乎不变。FESEM和小角度X射线衍射结果表明:溅射态薄膜的层与层之间存在明显的界面,具有良好的周期性,升高退火温度,晶粒尺寸增大,但仍保持周期性结构。薄膜的紫外-可见光吸收光谱表明:随着退火温度的升高,吸收边发生红移,光学带隙从溅射态的1.86eV减小到600℃时的1.59eV。

Multilayered(Ge/SiO2)15film was deposited on quartz by radio frequency(RF)magnetron sputtering technique,and then annealed at different temperatures.XRD and Raman results indicate that the as-deposited film is amorphous.When the film is annealed at 500℃,obvious crystal diffraction peaks occur,and then the crystallinity of the film increases.When the annealing temperature goes beyond 600℃,the crystallinity of the film remains stable.The results of the FESEM and small angle X-ray diffraction(SAXRD)show that the distinct interface between the layers is observed in the as-deposited film,exhibiting periodic structure.As the annealing temperature increases,the film still keeps periodic structure and its crystal size increases.The UV-VIS spectra suggest that increasing annealing temperature leads to the red shift of absorption edge,and optical band gap of as-deposited sample reduces from 1.86eV(as-deposited)to 1.59eV(600℃).