Martin-Luther-University Halle-Wittenberg, Institute of Physics, Von-Danckelmann-Platz 3, D-06120 Halle, Germany.
Nanotechnology. 2009 Dec 16;20(50):505705. doi: 10.1088/0957-4484/20/50/505705. Epub 2009 Nov 19.
Nanosized metal particles of various configurations embedded in surface regions of glass have great potential as nonlinear optical materials for photonic devices. We have prepared Ag/Au nanoparticles in core-shell configuration in soda-lime silicate glass by double-ion implantation and investigated their structural characteristics by anomalous small-angle x-ray scattering (ASAXS) and transmission electron microscopy. Measurements at x-ray energies slightly below the Au L(3) edge indicate the formation of bimetallic Ag/Au shells in some of the nanoparticles for high-dose ion implantation. An element-specific analysis of the ASAXS results allowed us not only to validate and quantify the core-shell structure, but simultaneously also the composition of the shells. Hollow nanoparticles were found for an Au-Ag implantation sequence, whereas an Ag-Au sequence generates a diluted core composition. The shift of the maximum position of optical absorption of the samples due to surface plasmon resonance of bimetallic nanoparticles, as monitored by optical spectroscopy, revealed the considerable influence of the respective particle configuration.
嵌入玻璃表面区域的各种形态的纳米金属颗粒在光子器件的非线性光学材料方面有很大的潜力。我们通过双离子注入在钠钙硅玻璃中制备了核壳结构的 Ag/Au 纳米颗粒，并通过反常小角 X 射线散射（ASAXS）和透射电子显微镜研究了它们的结构特征。在 X 射线能量略低于 Au L(3)边缘的测量表明，对于高剂量离子注入，一些纳米颗粒中形成了双金属 Ag/Au 壳。对 ASAXS 结果的元素特异性分析不仅允许我们验证和量化核壳结构，而且同时也量化了壳的组成。对于 Au-Ag 注入序列，发现了空心纳米颗粒，而 Ag-Au 序列则产生了稀释的核组成。通过光学光谱监测，由于双金属纳米颗粒的表面等离子体共振，样品的光吸收最大值的位移揭示了各自颗粒结构的相当大的影响。
