Dynamics of Bulk vs. Nanoscale WS_2: Local Strain and Charging Effects
  We measured the infrared vibrational properties of bulk and nanoparticle WS$_2$ in order to investigate the structure-property relations in these novel materials. In addition to the symmetry-breaking effects of local strain, nanoparticle curvature modifies the local charging environment of the bulk material. Performing a charge analysis on the \emph{xy}-polarized E$_{1u}$ vibrational mode, we find an approximate 1.5:1 intralayer charge difference between the layered 2H material and inorganic fullerene-like (IF) nanoparticles. This effective charge difference may impact the solid-state lubrication properties of nanoscale metal dichalcogenides. 
R.D. Luttrell (1), S. Brown (1), J. Cao (1), J.L. Musfeldt (1), R.   Rosentsveig (2), and R. Tenne (2) ((1) University of Te...