Seguini G, Curi J Llamoja, Spiga S, Tallarida G, Wiemer C, Perego M
Laboratorio MDM, IMM-CNR, Via C Olivetti 2, I-20864 Agrate Brianza (MB), Italy.
Nanotechnology. 2014 Dec 12;25(49):495603. doi: 10.1088/0957-4484/25/49/495603. Epub 2014 Nov 20.
Ultra-thin Au films with thickness (h) ranging from 0.5 to 6.0 nm were deposited at room temperature (RT) by means of e-beam evaporation on SiO2 and HfO2. Due to the natural solid-state dewetting (SSD) of the as-deposited films, Au nanoparticles (NPs) were formed on the substrates. By properly adjusting the h value, the size and the density of the Au NPs can be finely tuned. For h = 0.5 nm, spherical-like Au NPs with diameter below 5 nm and density in the order of 10(12) Au NPs cm(-2) were obtained without any additional thermal treatment independently from the substrate. The dependence of the Au NPs characteristics on the substrate starts to be effective for h ≥ 1.0 nm where the Au NPs diameter is in the 5-10 nm range and the density is around 10(11) Au NPs cm(-2). The effect of a subsequent high temperature (400-800 °C) annealing in N2 atmosphere on the Au NPs was investigated as well. For h ≤ 1.0 nm, the Au NPs characteristics evidenced an excellent thermal stability. Whereas the thermal treatment affects the cristallinity of the Au NPs. For the thicker films (2.0 ≤ h ≤ 6.0 nm), the thermal treatment becomes effective to induce the SSD. The proposed methodology can be exploited for the synthesis of Au NPs with diameter below 10 nm on different substrates at RT.
通过电子束蒸发在室温下将厚度（h）在0.5至6.0纳米范围内的超薄金膜沉积在二氧化硅和氧化铪上。由于沉积薄膜的自然固态去湿（SSD），在基板上形成了金纳米颗粒（NP）。通过适当调整h值，可以精细调节金纳米颗粒的尺寸和密度。对于h = 0.5纳米，无需任何额外热处理，无论基板如何，均可获得直径低于5纳米且密度约为10(12)个金纳米颗粒/平方厘米的球形金纳米颗粒。当h≥1.0纳米时，金纳米颗粒的特性对基板的依赖性开始显现，此时金纳米颗粒直径在5 - 10纳米范围内，密度约为10(11)个金纳米颗粒/平方厘米。还研究了随后在氮气气氛中进行400 - 800°C高温退火对金纳米颗粒的影响。对于h≤1.0纳米，金纳米颗粒的特性显示出优异的热稳定性。而热处理会影响金纳米颗粒的结晶度。对于较厚的薄膜（2.0≤h≤6.0纳米），热处理有效地诱导了固态去湿。所提出的方法可用于在室温下在不同基板上合成直径低于10纳米的金纳米颗粒。
