Preparation and characterization of Ag-coated cenospheres by magnetron sputtering method

In this paper, we show the feasibility of the magnetron sputtering deposition technique to grow 10–100-nm thick, uniform, continuous and well adhesive silver films on cenosphere particles so that the properties of the core particles can be suitably modified. Experiments were conducted with a magnetron sputtering deposition system in which a newly designed sample stage equipped with an ultrasonic vibration generator was used for the tumbling of cenosphere particles. The cenosphere particles are characterized by X-ray diffraction (XRD) analysis, field emission scanning electron microscope (FE-SEM) and inductively coupled plasma-atom emission spectrometer (ICP-AES) before and after the coating process. All results show the metal film has been successfully coated onto cenosphere particles. Under the given conditions, up to 3.0 wt.% silver was deposited on cenosphere particles measured by ICP-AES. The FE-SEM results indicate that at the micro-scale the relatively uniform, compact and well adhesive silver films with about 51 nm thickness were successfully deposited on cenosphere particles. The XRD analytic result indicates that the nanometer metal film has a face-centered cubic structure.