Thermogravimetry in a gradient magnetic field as an efficient quasi in situ method for studying magnetic phase formation: optimizing ε-Fe2O3 synthesis

Abstract

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.