凝態物理專題演講
Advanced Topics on Condensed Matter Physics
Department of Physics, NCU
Structural and magnetic properties of AgCu nanoclusters
Speaker
Peter Yen(顏聰文), NCU Ph.D. student
Department of Physics, National Central University
Date 2015.10.8 (Thur)
Time 14:00
Place S4-625
Abstract:
In this talk, I shall address some progress in structural and magnetic properties of AgCu bimetallic clusters that we have done recently. The lowest energy structures AgnCu38-n (n=0,..,38) were determined first by applying a state-of-the-art optimization algorithm [P.J. Hsu, S.K. Lai, J. Chem. Phys. 124 (2006) 0447110)] that was combined with an empirical potential, and the calculated structures are then used as initial input structures in Kohn-Sham spin-unrestricted density functional theory calculations for further relaxing their geometries. Both electronic and magnetic properties were analyzed. I have discovered unexpected net magnetic moments in some of these clusters. I proffer a plausible explanation in the context of point group theory in much the same idea as the Clemenger-Nilsson model except that we draw particular attention to clusters’ topologies and show how they affect the dispersion of valence electrons in occupying different molecular orbital energy levels, which, in effect, induces net magnetism.