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

通过紫外激光辐照制备的Ag和Ag/Au纳米粒子及特定阵列，揭示了制备条件、原子结构和光学性质之间的基本关系。特别是，ArF激光照射应该允许直接在玻璃表面下方产生纳米颗粒的高分辨率图案，这是特别感兴趣的，因为它们具有纳米等离子体激元的多种应用的高潜力。起始点是纯的和含Au的玻璃，其将通过Ag/Na离子交换过程用银离子掺杂。ArF准分子（193 nm）和用于比较的使用低于烧蚀阈值的能量密度的固态激光照射（405 nm）应该基于对在UV照射下金属离子的还原和颗粒的生长的基本过程的详细研究来提供稳定的纳米颗粒的产生。紫外缺陷、金属原子和纳米颗粒的形成将通过光谱学和其他方法来检测，颗粒的精确尺寸及其分布将通过SAXS、XRD和透射电子显微镜实验来确定。Ag/Au粒子的均匀性或核壳结构的存在必须通过Ag K边的反常小角X射线散射（ASAXS）实验来澄清，而Au-L3边的核和壳将通过这种方法分别计算。 在Ag K-边和Au L3-边的X射线吸收光谱（XAS）将被应用于确定纳米颗粒的非均匀原子结构，这对于所有纳米结构都是预期的。结构信息是通过两种互补的方法来获得的实验EXAFS谱的处理，这使得能够确定存在于各种物种或本地订单内的颗粒的Ag和Au原子的本地结构参数。此外，非常小的（< 2-5 nm）Ag和Ag/Au纳米粒子的3D模型将使用密度泛函理论（DFT）方法，使用平面波和赝势形式主义和朗之万分子动力学的方法构建。 通过Mie理论模拟表面等离子体共振的光谱，应该揭示与金属纳米结构的详细结构结果的直接相关性。这是为了允许由于UV激光照射而限定的等离子体光谱的生成。

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.