Effect of sintering temperature on the chemical bonding, electronic structure and electrical transport properties of β-Ga1.9Fe0.1O3 compounds

A model system, which is based on iron (Fe) doped gallium oxide (Ga2O3) (Ga1.9Fe0.1O3), has been considered to elucidate the combined effect of transition-metal ion doping and processing temperature on the chemistry, local structure and chemical bonding, and electrical transport properties of a wide band gap oxide (Ga2O3). The Ga1.9Fe0.1O3 compounds were synthesized using standard high-temperature solid state reaction method. The effect of processing conditions in terms of different calcination and sintering environments on the structural and electrical properties of Ga1.9Fe0.1O3 compounds is studied in detail. Structural characterization by Raman spectroscopy revealed that Ga1.9Fe0.1O3 compounds exhibit monoclinic crystal symmetry, which is quite similar to the intrinsic parental crystal structure, though Fedoping induces lattice strain. Sintering temperature (T-sint) which was varied in the range of 900-1200 degrees C, has significant impact on the structure, chemical bonding, and electrical properties of Ga1.9Fe0.1O3 compounds. Raman spectroscopic measurements indicate the proper densification of the Ga1.9Fe0.1O3 compounds achieved through complete Fe diffusion into the parent Ga2O3 lattice which is evident at the highest sintering temperature. The X-ray photoelectron spectroscopy validates the chemical states of the constituent elements in Ga1.9Fe0.1O3 compounds. The electrical properties of Ga1.9Fe0.1O3 fully controlled by T-sint, which governed the grain size and microstructural evolution. The temperature and frequency dependent electrical measurements demonstrated the salient features of the Fe doped Ga2O3 compounds. The activation energy determined from Arrhenius equation is similar to 0.5 eV. The results demonstrate that control over structure, morphology, chemistry and electrical properties of the Ga1.9Fe0.1O3 compounds can be achieved by optimizing T-sint. (C) 2021 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

Automated summary

This study investigated the combined effect of transition-metal ion doping and processing temperature on the properties of Ga1.9Fe0.1O3 compounds. It was found that sintering temperature significantly influenced the structure, chemical bonding, and electrical properties of the compounds. The results suggest that optimization of sintering temperature can control the properties of Ga1.9Fe0.1O3 compounds.