Laser ablation of a platinum target in water. II. Ablation rate and nanoparticle size distributions
Laser ablation of a platinum target in water. II. Ablation rate and nanoparticle size distributions
复制标题
DOI：
10.1063/1.2390641
复制
发表时间：
2006-12-01
影响因子：
3.2
通讯作者：
Koshizaki, Naoto
中科院分区：
文献类型：
--
作者：
Nichols, William T.;Sasaki, Takeshi;Koshizaki, Naoto
这是一系列三篇论文中的第二篇，研究了液体激光烧蚀（LAL）中纳米材料的形成。在这里，我们研究了激光波长和能量密度的质量产量和纳米粒子的尺寸分布的影响，通过激光烧蚀的铂靶浸没在水中。对于测试的所有波长，在10-70 J/cm（2）范围内的激光能量密度导致球形的、非聚集的铂纳米颗粒，其尺寸范围为1至30 nm。纳米颗粒的尺寸分布被发现是由两种模式，这是由于热蒸发和爆炸沸腾机制。较小尺寸模式的峰值在所有激光条件下几乎保持恒定在3 nm，这被认为是由于液体对蒸气羽流的强烈限制。较大尺寸的模式峰值在5-15 nm的范围内，具有强烈依赖于激光参数的群体。它的结论是，在许多早期的研究中报告的平均尺寸的变化的金属目标的LAL是从每个机制，而不是直接控制消融过程中的纳米粒子的相对量的结果。此外，观察到在大于10 J/cm（2）的能量密度下，对于1064 nm波长，铂纳米颗粒的产率显著更大。最大烧蚀率约为4.4毫克/小时，估计的烧蚀和收集效率为0.9微克/J。波长和能量密度的质量产量的依赖性被认为是主要依赖于爆炸机制的程度。(c)2006年，美国物理学会。
This is the second in a series of three papers examining nanomaterial formation in laser ablation in liquids (LAL). Here we study the effect of the laser wavelength and fluence on the mass yield and size distribution of nanoparticles prepared by laser ablation of a platinum target immersed in water. For all wavelengths tested, laser fluences in the range of 10-70 J/cm(2) resulted in spheroidal, nonagglomerated platinum nanoparticles with sizes ranging from 1 to 30 nm. Nanoparticle size distributions are found to be composed of two modes that are attributed to thermal vaporization and explosive boiling mechanisms. The peak of the smaller size mode remains nearly constant at 3 nm for all laser conditions, which is suggested to be due to the strong confinement of the vapor plume by the liquid. The larger size mode peaks in the range of 5-15 nm with a population that is strongly dependent on the laser parameters. It is concluded that changes in the mean size reported in many earlier studies on LAL of metal targets are a result of the relative quantity of nanoparticles from each mechanism rather than direct control over the ablation process. Additionally, it was observed that the yield of platinum nanoparticles was significantly larger for 1064 nm wavelength at fluences greater than 10 J/cm(2). The maximum ablation rate was approximately 4.4 mg/h, with an estimated ablation and collection efficiency of 0.9 mu g/J. Dependence of the mass yield on wavelength and fluence is seen to be dependent primarily on the extent of the explosive mechanism. (c) 2006 American Institute of Physics.