Table of Contents
Journal of Coatings
Volume 2013, Article ID 981515, 6 pages
http://dx.doi.org/10.1155/2013/981515
Research Article

A Study on the Thermodynamics of Grain Growth in R.F. Magnetron Sputtered NiO Thin Films

1Department of Physics, Catholicate College, Pathanamthitta, Kerala 689 645, India
2Department of Physics, D.B. College, Sasthamcotta, Kollam, Kerala 690 521, India

Received 22 March 2013; Revised 12 July 2013; Accepted 25 July 2013

Academic Editor: Mariana Braic

Copyright © 2013 I. Dhanya and B. Sasi. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Postdeposition annealing of thin nickel films synthesized using R.F. magnetron sputtering technique is carried in this study. The XRD analysis indicates that annealing of the nickel films leads to the formation of nickel oxide with a preferential growth along (200) plane. The oxidation mechanism is observed with a phase transformation and results in polycrystalline NiO films. The surface morphology of the thin films was investigated by scanning electron microscopy (SEM) and atomic force microscopy (AFM) as a function of annealing temperature. The studies indicate the formation of well-defined grain boundaries due to agglomeration of nanocrystallites. The films annealed in the range 573–773 K are found to be porous. The optical transmission spectra of the films annealed at 773 K exhibit interference effects for photon energies below the fundamental absorption edge. The optical studies indicate the existence of direct interband transition across a bandgap of 3.7 eV in confirmation with earlier band structure calculations.