Dresden 2003 – wissenschaftliches Programm
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CPP: Chemische Physik und Polymerphysik
CPP 2: Colloide, Nanopartikel und Kapseln
CPP 2.10: Vortrag
Montag, 24. März 2003, 12:30–12:45, ZEU/260
Size determination of nanoparticles using synchrotron radiation: New techniques and results — •C. Kumpf1, A. Stahl1, S. Joshi1, W. Weigand1, S.K. Kulkarni2, K. Hradil3, R. Neder3, and E. Umbach1 — 1Experimentelle Physik 2, Univ. Würzburg — 2Department of Physics, University Pune, India — 3Inst. für Mineralogie und Kristallstrukturlehre, Univ. Würzburg
Semiconductor nanoparticles are of increasing interest for both applied and fundamental research. In material science, e.g., they are used for fabricating thin film LEDs and solar cells. Particles with a size of 1-10 nm are of particular interest in fundamental research since they represent a size scale between solid state physics and molecular or cluster physics in which quantum size effects play an important role. A precise determination of the particle size is an important issue. Often local probes like TEM or AFM are used, which cannot give representative results of the mean particle size and have additional drawbacks. Other approaches, which make use of quantum size effects, inclose the risk of large systematical errors since the effective mass or tight-binding models used for data interpretation may fail in the 1-3 nm range. Potentially, diffraction methods are able to provide more precise structural information, provided special care is applied. We present new data obtained by normal and anomalous x-ray diffraction methods using particles which were prepared using a wet-chemical route. Results concerning structure, size and relaxation effects are addressed.