Controlled Formation and Growth Kinetics of Phase-Pure, Crystalline BiFeO₃ Nanoparticles^†

Abstract

In situ synchrotron X-ray powder diffraction is used to elucidate the formation mechanism of multiferroic BiFeO3 nanoparticles during moderate heat treatment at ambient pressure of an amorphous precursor. A wet chemical synthesis is used to obtain the precursor, formed after solvent elimination of an aqueous solution containing iron and bismuth nitrates and tartaric acid. The in situ experiments are performed at two reaction temperatures and two heating rates, both giving rise to the growth of BiFeO3 nanoparticles without going through any intermediate crystalline phases. A detailed XRD line profile intensity analysis as a function of time and temperature provides information on the nucleation rate, growth kinetics, and size distribution of the nanoparticles.

Morphology Control in van der Waals Epitaxy of Bismuth Telluride Topological Insulators

“…This disagreement may arise from the fact that the actual 𝐿 value for sample S2 can be different from the expected one, or that the RSM of the chosen symmetric Bragg reflection has different susceptibility to the 𝐿 value determined when using asymmetric reflections [1]. In either case, the low-intensity patterns were shown to be dominated by shape and orientation of the smallest sized domains present in the film, contrarily to the fwhm that is determined by size distribution weighted functions [19,20].…”

A simple formula for determining nanoparticle size distribution by combining small-angle X-ray scattering and diffraction results

“…Advances in nanoscience have demanded accurate measurements of particle size and size distribution as many physical and chemical properties of nanoparticle (NP) systems are size related (Borchert et al, 2005;Keshari & Pandey, 2008;Grassian, 2008;Schwung et al, 2014;Schmidt et al, 2016;Clarke et al, 2018;Kabir et al, 2022). In the search for size determination methods, a simple but essential question is recurrent in X-ray analysis of polydisperse systems of crystalline NPs (Ingham, 2015;Gamez-Mendoza et al, 2017;Freitas Cabral et al, 2020;Kaduk et al, 2021). In the wideangle X-ray scattering (WAXS) region, what parameter of the particle size distribution (PSD) is determined by the diffraction peak width?…”