Multi-scale analysis of the nanostructured granular solid CoO–Ag by TEM and EELS Original Research Article

Nanostructured granular solid consisting of antiferromagnetic CoO particles embedded in a metallic medium (Ag) has been investigated by both transmission electron microscopy (TEM) and electron energy loss spectroscopy (EELS) on a multiple scale. Quantitative composition determination was carried out by energy dispersive X-ray spectroscopy (EDXS) for Ag and Co, and by EELS for oxygen and Co quantification. Because of the complex morphology of the indicated CoO–Ag granular system, only a detailed analysis of the spatial variation of the EELS signals can provide information on the particle size and distribution. A mean size of 5 nm for CoO particles has been evaluated. The oxidation state of Co has also been studied using fine structures on EELS spectra. CoO phase is clearly identified as the oxide but appears mixed with small metallic Co area.