Metal nanoparticles prepared by excimer and solid state laser irradiation in silicate glass: dependence of atomic structure, strength of interaction with matrix and properties of nanoparticles upon their sizes, spatial configurations and the preparation p

揭示了紫外光照射玻璃中制备的Ag和Ag/Au纳米粒子及其特定阵列的制备条件、原子结构和光学性质之间的基本关系。特别是，ArF激光照射应该允许在玻璃表面下直接产生高分辨率的纳米颗粒图案，这是特别令人感兴趣的，因为它们在纳米等离子体的多种应用中具有很高的潜力。起始点是纯的和含金的玻璃，通过银/钠离子交换过程在玻璃中掺杂银离子。作为比较，使用低于烧蚀阈值的通量的固体激光(405 Nm)照射ArF准分子(193 Nm)应该能够基于对紫外光照射下金属离子还原和颗粒生长的基本过程的详细研究来生成稳定的纳米颗粒。UV缺陷、金属原子和纳米颗粒的形成将通过光学光谱和进一步的方法进行检测，对于一些选定的样品，需要通过SAXS、X射线衍射和透射电子显微镜实验来确定颗粒的精确尺寸和分布。在AgK边的反常小角X射线散射(ASAXS)实验必须证实是否存在均匀的或核壳结构的Ag/Au粒子，而Au-L3边的核和壳将用这种方法分别计算。在银K边和Au L3边的X射线吸收光谱(XAS)将被用来确定纳米粒子的非均匀原子结构，这是所有纳米结构所预期的。结构信息是通过两种互补的方法处理实验EXAFS谱获得的，这使得能够确定存在于粒子内不同物种或局部有序中的银和金原子的局域结构参数。此外，我们还将使用密度泛函理论(DFT)方法，结合平面波和赝势形式，以及朗之万分子动力学的方法，构建非常小的(&lt；2-5 nm)Ag和Ag/Au纳米粒子的三维模型。用Mie理论模拟表面等离子激元共振的光谱应该与金属纳米结构的详细结构结果直接相关。这是为了允许由于紫外线激光照射而产生明确的等离子体光谱。

The basic relations between preparation conditions, atomic structure and optical properties should be revealed for Ag and Ag/Au nanoparticles and specific arrays as prepared by UV laser irradiation in glasses. Especially, ArF laser irradiation should allow the generation of high-resolution patterns of nanoparticles immediately below the surface of glasses, which are of specific interest because of their high potential for manifold applications of nanoplasmonics. The starting point are pure and Au containing glasses, which will be doped with silver ions by means of Ag/Na ion exchange processes. ArF excimer (193nm) and for comparison solid state laser irradiation (405nm) using fluences below the ablation threshold should provide the generation of stabilized nanoparticles based on detailed investigations of elementary processes of reduction of metal ions and the growth of particles under UV irradiation. The formation of UV defects, metal atoms and nanoparticles will be detected by optical spectroscopy and further methods.The precise sizes of particles and their distribution should be determined by means of SAXS, XRD and transmission electron microscopy experiments for some selected samples. The existence of homogeneous or of core-shell Ag/Au particles has to be clarified by anomalous small angle X-ray scattering (ASAXS) experiments at the Ag K-edge and the Au-L3-edge core and shell will be calculated separately by this method for such species. The X-ray absorption spectroscopy (XAS) at Ag K-edge and Au L3-edge will be applied to determine the inhomogeneous atomic structure of nanoparticles that is to be expected for all nanostructures. The structural information are to be obtained by two complementary approaches for the processing of experimental EXAFS spectra, which enables to determine local structure parameters of Ag and Au atoms existing in various species or local orders inside the particles. Furthermore, 3D models of very small (< 2-5 nm) Ag and Ag/Au nanoparticles will be constructed using the density functional theory (DFT) method using plane waves and pseudopotential formalisms and by the method of Langevin molecular dynamics. The simulation of optical spectra of surface plasmon resonances by means of Mie-Theory should reveal a direct correlation with the detailed structural results of metal nanostructures. This is to allow a defined generation of plasmonic spectra due to UV laser irradiation.