Barberio M, Scisciò M, Vallières S, Veltri S, Morabito A, Antici P
INRS-EMT, 1650 Boul. Lionel Boulet, Varennes, Canada.
INFN and University of Rome, Via Scarpa 14, 00161, Roma, Italy.
Sci Rep. 2017 Oct 2;7(1):12522. doi: 10.1038/s41598-017-12782-w.
We present a method for the synthesis of micro-crystals and micro-structured surfaces using laser-accelerated protons. In this method, a solid surface material having a low melting temperature is irradiated with very-short laser-generated protons, provoking in the ablation process thermodynamic conditions that are between the boiling and the critical point. The intense and very quick proton energy deposition (in the ns range) induces an explosive boiling and produces microcrystals that nucleate in a plasma plume composed by ions and atoms detached from the laser-irradiated surface. The synthesized particles in the plasma plume are then deposited onto a cold neighboring, non-irradiated, solid secondary surface. We experimentally verify the synthesizing methods by depositing low-melting-material microcrystals - such as gold - onto nearby silver surfaces and modeling the proton/matter interaction via a Monte Carlo code, confirming that we are in the above described thermodynamic conditions. Morphological and crystallinity measurements indicate the formation of gold octahedral crystals with dimensions around 1.2 μm, uniformly distributed onto a silver surface with dimensions in the tens of mm. This laser-accelerated particle based synthesis method paves the way for the development of new material synthesis using ultrashort laser-accelerated particle beams.
我们提出了一种使用激光加速质子合成微晶和微结构表面的方法。在该方法中，用极短的激光产生的质子辐照具有低熔点温度的固体表面材料，在烧蚀过程中引发介于沸点和临界点之间的热力学条件。强烈且非常快速的质子能量沉积（在纳秒范围内）引发爆炸式沸腾，并产生在由从激光辐照表面分离的离子和原子组成的等离子体羽流中形核的微晶。然后，等离子体羽流中合成的粒子沉积到相邻的冷的、未辐照的固体二次表面上。我们通过将低熔点材料微晶（如金）沉积到附近的银表面上并通过蒙特卡罗代码对质子/物质相互作用进行建模来实验验证合成方法，证实我们处于上述热力学条件下。形态学和结晶度测量表明形成了尺寸约为1.2μm的金八面体晶体，均匀分布在尺寸为几十毫米的银表面上。这种基于激光加速粒子的合成方法为使用超短激光加速粒子束开发新材料合成铺平了道路。
