Vibration Dynamics of Supra‐Crystals of Cobalt Nanocrystals Studied With Femtosecond Laser Pulses

Abstract

Face-centered cubic (fcc) Supra-crystals and disordered assemblies of Co nanocrystals have their time-dependent reflectivity compared using time-resolved confocal microscopy. The differential reflectivity exhibits a behavior strongly dependent on mesoscopic organization, an effect associated with the collective coherent vibration of the cobalt nanocrystals in the fcc superstructure. The coherent vibration is mediated by interdigitated aliphatic chains acting as nanosprings.