Localization and charge state of metal ions in carbon nanostructures of europium bis-phthalocyanine pyrolysed derivatives

In the experiments of Mössbauer spectroscopy, transmission electron microscopy (TEM) and atomic force microscopy (AFM) the morphology and structurization of the carbon phase, the charge state of europium and the dynamic properties of europium bis-phthalocyanine pyrolysed derivatives, including the Debye temperature, were revealed. It was found that the pyrolysis of europium bis-pthalocyanine resulted in the amorphous carbon matrix and nanoscaled graphene clusters both forming turbostratic carbon phase. The europium ions in the charge state Eu$^{3+}$/Eu$^{2+}$ were detected. The data indicated that localization of Eu ions took place between layers of graphenes similar to graphite intercalation compounds. It was shown that an isomeric shift, linewidths and the magnitude of the resonant absorption are essential characteristics of structural transformations at the pyrolysis of rare earth bis-phthalocyanines.