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Nanostrukturen und Grenzflächen Poster: Do., 13:00–15:30 D-P275
Formation of optically active gold nanoparticles in silicate glasses: SAXS
studies on synchrotron activated growth
Maik Eichelbaum 1 , Klaus Rademann 1 , Armin Hoell 2 , Dragomir M. Tatchev 1 ,
J. Banhart 2
1 Institut für Chemie, Humboldt-Univ., Brook-Taylor-Straße 2, 12489 Berlin – 2 Hahn-
Meitner-Institut, Department of Structural Research, 14109 Berlin
Gold clusters can be generated on demand in metal doped silicate glasses by a newly developed
non-thermal activation process based on synchrotron radiation. Nanosized gold
particles were obtained in soda lime silicate glasses containing 0.01 mol% Gold(III)chloride.
Gold nanoparticles grow during annealing up to 30 min at 550 ◦ C in regions
previously irradiated with 32 keV X-rays. The nanoparticles can be probed by their
characteristic surface plasmon resonance in the UV/Vis spectrum [1]. In co-operation
with Dr. Bernd Löchel of the Anwenderzentrum für Mikrosystemtechnologie (AZM),
we also succeeded recently to write plasmonic microstructures into the glass by exposure
through an x-ray mask. Small plasmonic metal clusters in transparent matrices
could play an important role in optoelectronics.
Our goal is the measurement of the optical characteristics of the so produced metal
clusters as a function of the size, shape, topology and the dielectric environment as well
as their optimization for the use in optoelectronic circuits. As a check of the cluster sizes
and thus for the controlling of the optical characteristics of our materials it is necessary
to understand the growth process of the metal particles. Therefore homogeneity, size
distributions and thus the growth of the clusters were examined by (anomalous) small
angle x-ray scattering ((A)SAXS) as a function of the temperature and duration of the
thermal treatment of the glasses. After background subtraction, the scattering curves
were fit with the spherical particle model by the maximum entropy method. Figure 1
shows the differential volume fraction size distributions for two annealing times. It can
be seen that nanoparticle size and volume fraction increase with annealing time and
that very sharp size distributions were achieved.
[1] M. Eichelbaum et al., Angew. Chem. Int. Ed. 44 (2005) 7905
Fig. 1: Size distributions of Au particles in synchrotron activated
gold ruby glass after different annealing times.