EMR study and superposition model analysis of Cr³⁺ and Fe³⁺ impurity ions in mullite powders used in aerospace industry

In this work, the electron magnetic resonance (EMR) spectra of the mullites powders were measured for different grain sizes (0.07 and 0.12 mm). We have used EMR spectroscopy at X-band, combined with superposition model (SPM) calculations to reveal electronic structure and establish correlations between structure, and surroundings of these complexes.