Multifunctional GaFeO3 Obtained via Mechanochemical Activation Followed by Calcination of Equimolar Nano-System Ga2O3-Fe2O3

The equimolar oxide mixture beta-Ga2O3-alpha-Fe2O3 was subjected to high-energy ball milling (HEBM) with the aim to obtain the nanoscaled GaFeO3 ortho-ferrite. X-ray diffraction, Fe-57 Mossbauer spectroscopy, and transmission electron microscopy were used to evidence the phase structure and evolution of the equimolar nano-system beta-Ga2O3-alpha-Fe2O3 under mechanochemical activation, either as-prepared or followed by subsequent calcination. The mechanical activation was performed for 2 h to 12 h in normal atmosphere. After 12 h of HEBM, only nanoscaled (similar to 20 nm) gallium-doped alpha-Fe2O3 was obtained. The GaFeO3 structure was obtained as single phase, merely after calcination at 950 degrees C for a couple of hours, of the sample being subjected to HEBM for 12 h. This temperature is 450 degrees C lower than used in the conventional solid phase reaction to obtain gallium orthoferrite. The optical and magnetic properties of representative nanoscaled samples, revealing their multifunctional character, were presented.

Automated summary

The equimolar oxide mixture beta-Ga2O3-alpha-Fe2O3 was processed by high-energy ball milling to obtain nanoscaled GaFeO3 ortho-ferrite. After 12 hours of HEBM, only nanoscaled gallium-doped alpha-Fe2O3 was obtained, with the GaFeO3 structure being achieved after subsequent calcination.