X-ray diffraction line profile analysis: A microstructural study in polymorphic TiO2

The microstructural properties of polycrystalline materials can be indirectly analyzed through X-ray diffraction data. To this, the diffraction-line broadening phenomena is taking into account as a basis to develop theoretical approaches focusing on determinate defects into the crystal structure (e.g., dislocations, stacking and twin faults, lattice distortions, vacancies) as well as their concentrations and distributions. In this study, X-ray Line Profile Analysis (XLPA) from two pure samples of anatase and rutile TiO2 powders were conducted to look at their microstructural characterization using the classical Williamson Hall (WH) and Warren Averbach (WA) methods. WH microstructural analysis indicates that the calculated strain contribution at the upper limit is 1.89% and 1.31% for anatase and rutile, respectively, while the root mean-square of the variations in the strain was determined using the WA method to obtain percentages in about 0.23% and 0.30% for anatase and rutile, respectively. The area-weighted mean column length, < t >(Area), was determine using WA obtaining 42 nm and 91 nm in anatase and rutile phases, respectively. (C) 2019 Elsevier Ltd. All rights reserved.