含氦纳米晶钛膜的PBS和XRD研究

PBS and XRD study on helium-charged nanocrystalline titanium film

为研究不同晶粒尺寸纳米钛膜的储氦行为,在He-Ar混合气体下,用磁控溅射方法沉积纳米晶钛膜,利用PBS(proton backscattering)、XRD(X-ray diffraction)对膜的氦含量和微观结构及晶粒大小进行了研究。结果表明:在其它实验参数不变的情况下,当沉积温度从60℃升至350℃时得到均匀分布的含氦量(指原子百分比)从38.6%逐渐降至9.2%的钛膜,其平均晶粒由13.1nm增加到44.2nm;当He/Ar分压比分别为6、10、15、19时得到均匀分布的含氦量分别为17.6%、47.2%、48.3%和38.6%的钛膜。He的引入引起(002)晶面衍射峰向小角度移动,但(100)晶面衍射峰不变,即晶胞参数c增加,a不变化;随膜中He含量的增加,衍射峰展宽,晶粒变小,显示出氦的掺入有抑制纳米晶粒长大的趋势。

Helium-charged nanocrystalline titanium films were deposited by He-Ar magnetron sputtering. The helium content, microstructure and average grain size of the nanocrystalline titanium films were studied by PBS （proton backscattering） and XRD （X-ray diffraction）. The results indicated that under the same deposition parameters except the substrate temperature, which increased from 60℃ to 350℃, the helium content decreased gradually from 38.6% to 9.2% and the grain size increased from 13.1 nm to 44.2 nm. When the flux ratio of He/At was 6, 10, 15 and 19, helium content of the films was 17.6%, 47.2%, 48.3% and 38.6%, respectively. The Bragg peak of （002） crystal plane in the film had a slight shift to of the left comparing with that of the pure Ti film, while Bragg peak of （100） crystal plane did not change. This indicated that the lattice parameter c increased but the lattice parameter a remained the same. With increasing helium content in the film, the diffraction peaks broadened and grain sizes decreased. These further indicated that the incorporation of helium has an inhibition function to the grain growth of the film.