On the characterization of sculptured columnar Mn thin films; correlation between nanostructure and the optical and electrical properties using experimental and simulation results

Abstract

Mn columnar (nanorod shaped) thin films of 40 and 150 nm thicknesses were deposited on glass substrates at different deposition angles, using oblique angle deposition technique. The concept of local homogenization proposed by Bruggeman is used for optical analyses of these samples. Results of this simulation method are compared with the experimental data and values for void fraction and film thickness are predicted. In addition, using the perturbation simulation method, variation of relative resistance of these thin films was obtained as a function of material inclusion. It is observed that both simulation and experimental results show that the thinnest samples with the least amount of material inclusion have the highest electrical resistance. Results showed a rise at about 30° deposition angle, which may be attributed to the surface diffusion effect or thermal vibration causing rearrangement of atoms as well as crystallographic available sites for relaxation of adatoms deposited at this certain direction, though this requires a thorough investigation.

Keywords:

• Mn nanorods
• sculptured thin films
• Bruggeman formalism
• optical properties
• electrical resistance

Acknowledgements

This work was carried out with the support of the University of Tehran. HS is grateful to the Centre of Excellence for Physics of Structure and Microscopic Properties of Matter, Department of Physics, University of Tehran for partial support of this work. Partial support of this work by Iran National Science Foundation (INSF) is greatly appreciated.