REVIEW Structural characterization of polycrystalline thin films by X-ray diffraction techniques Akhilesh Pandey 1, * , Sandeep Dalal 1 , Shankar Dutta 1 , and Ambesh Dixit 2 1 Solid-State Physics Laboratory, DRDO, Lucknow Road, Timarpur, Delhi 110054, India 2 Department of Physics, Indian Institute of Technology, Jodhpur, Rajasthan, India Received: 9 August 2020 Accepted: 28 November 2020 Published online: 3 January 2021 Ó The Author(s), under exclusive licence to Springer Science+Business Media, LLC part of Springer Nature 2021 ABSTRACT X-ray diffraction (XRD) techniques are powerful, non-destructive characteriza- tion tool with minimal sample preparation. XRD provides the first information about the materials phases, crystalline structure, average crystallite size, micro and macro strain, orientation parameter, texture coefficient, degree of crys- tallinity, crystal defects etc. XRD analysis provides information about the bulk, polycrystalline thin films, and multilayer structures, which is very important in various scientific and material engineering fields. This review discusses the diffraction related phenomena/principles such as powder X-ray diffraction, and thin-film/grazing incidence X-ray diffraction (GIXRD) comprehensively for thin film samples which are used frequently in various branches of science and technology. The review also covers few case studies on polycrystalline thin-film samples related to phase analysis, preferred orientation parameter (texture coefficient) analysis, stress evaluation in thin films and multilayer, multiphase content identification, bifurcation of multiphase on multilayer samples, depth profiling in thin-film/ multilayer structures, the impact of doping effect on structural properties of thin films etc., comprehensively using GIXRD/XRD. 1 Introduction The thin-film characteristics are quite different from the respective bulk counterparts. Materials, having at least one of the dimensions in the nanometer scale (less than 100 nm), are known as nanostructured materials, where properties are significantly different because of geometrical restrictions, causing novel physical and chemical properties. Thin films (either it is polycrystalline, or single crystal (epitaxial) or amorphous form) of a thickness ( \ 1 lm), possess higher surface energy due to its large surface to volume ratio; thus responsible for different physical, material and chemical properties than their bulk counterpart [1, 2]. This scope of tailoring materials’ to create the desired physical properties led to large research activities in many areas such as microelec- tronics, optoelectronics, and sensors [3]. In these devices, precise growth of multiple layers of films (in either amorphous, polycrystalline or epitaxial form) of polymers, metals, semiconductors, and insulators is essential to get the desired outcome. These films Address correspondence to E-mail: akhilesh.physics@gmail.com https://doi.org/10.1007/s10854-020-04998-w J Mater Sci: Mater Electron (2021) 32:1341–1368 Review