Mechanism of the formation of copper‐containing fractal‐like crystallites in metal‐organic thin films: Shape simulation and XANES analysis

Abstract

Phone: þ7 928 771 66 57, Fax: þ7 863 297 51 20Copper-containing thin films were synthesized by a citrate sol-gel method using ethylene glycol. The evolution of the shape and local atomic structure of the copper-containing fractal crystallites at different stages of growth was investigated by the combination of experimental and theoretical techniques. A surface morphological study of the deposited film samples was carried out using SEM. It revealed the evolution of the crystallite structures as a function of annealing temperature. To describe this mechanism diffusion-limiting aggregation and cluster-cluster models were used. X-ray absorption spectroscopy (XANES) was applied to show the dynamics of the local atomic structure of Cu ion and the copper oxidation state at different stages of crystallites formation. It was found that at temperatures up to 250 8C the Cu 2 Cl(OH) 3 (atacamite phase) and chelate complex are formed. With temperature increases changes in the local atomic structure as well as in morphology take place and at 500 8C CuO formed. As a result of these processes, the fractal organization of the other level was observed.

Sol-Gel Materials for Electrochemical Applications: Recent Advances

“…Several advantages can be expected in the development of sensitive gas sensors. In the context, of the sensors controlling the impurities via stoichiometry, low-temperature fabrication should provide better control over the structural morphology [6][7][8][9][10][11][12]. These factors contribute to low conductivity and high purity for excellent sensitivity.…”

Fabrication of Gas-Sensor Chips Based on Silicon–Carbon Films Obtained by Electrochemical Deposition

“…The purpose of this work is to compare the gas sensitive characteristics of two different types gas sensors.We used CuO, as it the most widely-studied oxide of all copper oxides in terms of sensing applications. CuO is a typical p-type semiconductor with many remarkable properties, including catalytic activity and high stability [21][22][23][24]. The investigation results show that CuO is stable under exposure to various gases (nitrogen oxides, carbon oxides, volatile organic compounds, ammonia, etc.…”