Volume 533, Issue 12 2100358
Research Article

How the Complex Network of Specklegram Deciphers Intra-Film Thermal Induced Dynamics?

Sankaranarayana Iyer Sankararaman

Corresponding Author

Sankaranarayana Iyer Sankararaman

Department of Optoelectronics, University of Kerala, Kariavattom, Trivandrum, Kerala, 695581 India

[email protected]

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First published: 07 November 2021

Abstract

The present work deciphers the potential of the graph and its features in the speckle-based nondestructive evaluation of intra film thermal-induced dynamics. The molybdenum oxide film, prepared by sputtering technique, containing nanorods is subjected to thermal stress from 30–50 °C and the specklegrams are recorded. The co-occurrence matrix (CM) and heat map analyses of the specklegrams by dividing the temperature range into four intervals of 5 °C each reveal that the thermal stress drives the film from a less stable to a more stable state from the third to the fourth temperature interval. The CM analysis indicates the thermal-induced rearrangements among the nanorods of the film. By extracting frames from the videograph of the speckle pattern during temperature variation, a complex network is constructed, taking the middle column of each frame as a node. The graph features also become minimum in the third interval and increase in the fourth interval revealing that the film moves to a more ordered state under thermal stress. The analysis of the specklegram by CM, heat map, and graph suggests that graph features present a high sensitivity compared to the other methods.

Conflict of Interest

The author declares no conflict of interest.

Data Availability Statement

Data sharing is not applicable to this article as no new data were created or analyzed in this study.

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