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Title: Fractal and multifractal characteristics of swift heavy ion induced self-affine nanostructured BaF{sub 2} thin film surfaces

Fractal and multifractal characteristics of self-affine surfaces of BaF{sub 2} thin films, deposited on crystalline Si 〈1 1 1〉 substrate at room temperature, were studied. Self-affine surfaces were prepared by irradiation of 120 MeV Ag{sup 9+} ions which modified the surface morphology at nanometer scale. The surface morphology of virgin thin film and those irradiated with different ion fluences are characterized by atomic force microscopy technique. The surface roughness (interface width) shows monotonic decrease with ion fluences, while the other parameters, such as lateral correlation length, roughness exponent, and fractal dimension, did not show either monotonic decrease or increase in nature. The self-affine nature of the films is further confirmed by autocorrelation function. The power spectral density of thin films surfaces exhibits inverse power law variation with spatial frequency, suggesting the existence of fractal component in surface morphology. The multifractal detrended fluctuation analysis based on the partition function approach is also performed on virgin and irradiated thin films. It is found that the partition function exhibits the power law behavior with the segment size. Moreover, it is also seen that the scaling exponents vary nonlinearly with the moment, thereby exhibiting the multifractal nature.
Authors:
;  [1] ; ;  [2]
  1. Department of Physics, University of Allahabad, Allahabad 211002 (India)
  2. Nanotechnology Application Centre, University of Allahabad, Allahabad 211002 (India)
Publication Date:
OSTI Identifier:
22482315
Resource Type:
Journal Article
Resource Relation:
Journal Name: Chaos (Woodbury, N. Y.); Journal Volume: 25; Journal Issue: 8; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ATOMIC FORCE MICROSCOPY; BARIUM FLUORIDES; FLUCTUATIONS; FRACTALS; HEAVY IONS; IRRADIATION; MEV RANGE 100-1000; MORPHOLOGY; NANOSTRUCTURES; NONLINEAR PROBLEMS; PARTITION FUNCTIONS; ROUGHNESS; SPECTRAL DENSITY; SURFACES; TEMPERATURE RANGE 0273-0400 K; THIN FILMS