Structural, thermal, 57Fe and 151Eu Mössbauer studies of Eu2O3–Fe2O3 ceramic nanostructures

Abstract

xEu2O3–(1−x)α-Fe2O3 (x=0.1, 0.3, 0.5, and 0.7) nanoparticle system was successfully synthesized by mechanochemical activation of Eu2O3 and α-Fe2O3 mixtures for 0–12 h of ball milling time. The investigations aimed at exploring the formation of magnetic ceramic nanostructures, which are of crucial importance for catalysis and sensing applications. X-ray powder diffraction (XRD),as well as 57Fe and 151Eu Mössbauer spectroscopy and thermal analysis by differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA) was used to study the phase evolution of xEu2O3–(1−x)α−Fe2O3 nanoparticle system under the mechanochemical activation process. Rietveld refinement of the XRD patterns yielded the values of the particle size as a function of composition and milling times and indicated the formation of the EuFeO3 perovskite for large x values and long milling times. The 57Fe Mössbauer studies showed that the spectrum of the mechanochemically activated composites evolved from a sextet for hematite to sextets and a doublet upon duration of the milling process with europium oxide. The 151Eu Mössbauer investigations showed that the isomer shift decreased with increasing milling time for all molar concentrations employed. These results correlate well with the DSC/TGA analysis, which shows the consumption of hematite and the formation of EuFeO3 in the system under investigation.