Thermogravimetry in a Gradient Magnetic Field as an Efficient Quasi In Situ Method for Studying Magnetic Phase Formation: Optimizing ε-Fe2O3 Synthesis

In this study, we present a principal methodology for semi quantitative analysis of magnetic phase composition during thermogravimetry under a gradient magnetic field, specifically in cycling mode. This approach is demonstrated using Fe-Si-O xerogels, in which magnetic nanophases such as ε-, γ-, and α-Fe₂O₃ can coexist and transform into each other. We introduce a novel, time-efficient quasi in situ approach to identify and optimize heat treatment conditions for synthesizing ε-Fe₂O₃ as a single phase, a material with significant industrial demand. Our results provide a valuable framework for advancing the controlled synthesis of magnetic compounds.