Structure of Yttrium Bis-Phthalocyanine Pyrolyzed Derivatives

Abstract

Pyrolyzed derivatives of yttrium bis-phthalocyanine are studied by small-angle neutron scattering, atomic force microscopy and infrared spectroscopy. Completely destroying bis-phthalocyanine molecules, the pyrolysis process forms thermally stable structures, the intrinsic density and packing of which are determined by the temperature. According to neutron data, during low-temperature pyrolysis (below 1000°C), loose chain structures dominate which consist of small carbon clusters; however, during high-temperature pyrolysis (1000–1500°C), carbon globules, creating branched fractal-type aggregates, are formed. In addition to the data on neutron scattering, the surfaces of pyrolyzed films were visualized by atomic force microscopy to study the fractal properties of the surface as a function of the pyrolysis temperature.