Periodicity and Atomic Ordering in Nanosized Particles of Crystals

• CHESS Home
• CESR
• ERL
• G-Line
• MacCHESS
• CLASSE Seminars
•  

Valeri Petkov - Dept of Physics
Central Michigan University

Abstract:
Knowledge of the atomic-scale structure is an important prerequisite to understanding, predicting and improving properties of materials. When materials are bulk crystals, single or powders, it is easily obtained by traditional (Bragg) x-ray diffraction. However, when the physical size of crystals is reduced to nanoscale dimensions Bragg x-ray diffraction is difficult to apply. The reason is that the diffraction patterns of nanosized particles of crystals show a very limited number of Bragg peaks, if any, and a very pronounced diffuse component. The problem may be solved by employing a non-traditional approach involving high-energy x-ray diffraction and atomic pair distribution function data analysis. In the talk, the essentials of this approach will be introduced and its great potential demonstrated with results from several recent studies on nanosized metallic (Au, PtPd), oxide (BaTiO₃, V2O₅, TiO₂ and biogenic MnOx), semiconductor (CdTe, CdSe) and organic (PAMAM dendrimers) particles.