Alkynyl-ruthenium based azo-organometallics: Thermal evolution of thin films microstructure

Alkynyl-ruthenium based azo-organometallics were studied in form of powders and thin layers obtained by conventional spin coating from solution. X-ray diffractometry revealed partly crystalline structure of powders while corresponding films were amorphous. Next, the films were subjected to a programmed heating and cooling. Meanwhile, their optical properties were monitored in situ using spectroscopic ellipsometry. It was found that upon thermic treatment films spontaneously adopted a crystalline structure, different from previously observed in the case of starting powders. This structure depended on chemical composition of a particular alkynyl-ruthenium compound.