Date of Graduation

Fall 2014

Degree

Master of Science in Materials Science

Department

Physics, Astronomy and Materials Science

Committee Chair

Kartik Ghosh

Keywords

nickel-nickel oxide, thin films, nanocomposite, transparent conductors, ferromagnetism, super paramagnetism

Subject Categories

Materials Science and Engineering

Abstract

Metal-metal oxide nanocomposites are very important for today's industrial and research field. Nanocomposite of nickel (Ni)-nickel oxide (NiO) films have potential applications including chemical sensor, bio sensors, infrared detectors, smart windows, and solar cells. It is very important to understand how to synthesize and modify the process parameters to get optimum materials. It is also important to characterize and understand the physical properties of these materials. The purpose of this thesis is to synthesize Ni-NiO thin films and characterized them for electronic applications. Nanocomposite Ni-NiO thin films were grown using pulsed laser deposition technique using a nickel target at four different oxygen pressures via 10-4 mbar, 50x10-3 mbar, 10-3 mbar, and 10-2 mbar of oxygen pressure and at temperature of 500 C. Nickel thin film in absence of oxygen and at 500 C is also grown. High quality Ni-NiO nanocomposite thin films were obtained which were confirmed by X-Ray Diffraction and Raman spectroscopy. UV-visual absorption spectroscopy data shows that the nanocomposite films are transparent semiconductors with the same band gap but a different absorbance. Magnetization data collected using a superconducting quantum interference device (SQUID) magnetometer in conjunction with electronic data shows that these Ni-NiO nanocomposite thin films have ferromagnetic, paramagnetic, and super paramagnetic properties. Resistivity of such thin films is varied by a large range from 107Ωm to 10-5 Ωm. Nanocomposite thin films of Ni-NiO could be useful for future spintronic and optoelectronic devices.

Copyright

© Laudari Prasad Amrit

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