Laser Zentrum Hannover e.V., Hollerithallee 8, 30419 Hannover, Germany.
Nanotechnology. 2009 Nov 4;20(44):445603. doi: 10.1088/0957-4484/20/44/445603. Epub 2009 Oct 5.
The generation of colloids by laser ablation of solids in a liquid offers a nearly unlimited material variety and a high purity as no chemical precursors are required. The use of novel high-power ultra-short-pulsed laser systems significantly increases the production rates even in inflammable organic solvents. By applying an average laser power of 50 W and pulse durations below 10 ps, up to 5 mg min(-1) of nanoparticles have been generated directly in acetone, marking a breakthrough in productivity of ultra-short-pulsed laser ablation in liquids. The produced colloids remain stable for more than six months. In the case of yttria-stabilized zirconia ceramic, the nanoparticles retain the tetragonal crystal structure of the ablated target. Laser beam self-focusing plays an important role, as a beam radius change of 2% on the liquid surface can lead to a decrease of nanoparticle production rates of 90% if the target position is not re-adjusted.
通过在液体中激光烧蚀固体来生成胶体提供了几乎无限的材料种类和高纯度，因为不需要任何化学前体。使用新型高功率超短脉冲激光系统即使在易燃有机溶剂中也能显著提高生产速率。通过施加平均激光功率为 50 W 和脉冲持续时间低于 10 ps 的激光，在丙酮中直接生成了高达 5 mg min(-1)的纳米颗粒，这标志着在液体中超短脉冲激光烧蚀的生产率取得了突破。所生成的胶体在超过六个月的时间里保持稳定。在氧化钇稳定的氧化锆陶瓷的情况下，纳米颗粒保留了被烧蚀的靶材的四方晶体结构。激光束自聚焦起着重要作用，如果不重新调整靶材位置，液体表面上的光束半径变化 2%就会导致纳米颗粒的生成速率降低 90%。
