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)(Ga_1.9Fe_0.1O₃),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 Ga_1.9Fe_0.1O₃ 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 Ga_1.9Fe_0.1O₃ compounds is studied in detail.Structural characterization by Raman spectroscopy revealed that Ga_1.9Fe_0.1O₃ 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℃,has significant impact on the structure,chemical bonding,and electrical properties of Ga_1.9Fe_0.1O₃ compounds.Raman spectroscopic measurements indicate the proper densification of the Ga_1.9Fe_0.1O₃ 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 Ga_1.9Fe_0.1O₃ compounds.The electrical properties of Ga_1.9Fe_0.1O₃ 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 0.5 e V.The results demonstrate that control over structure,morphology,chemistry and electrical properties of the Ga_1.9Fe_0.1O₃ compounds can be achieved by optimizing T_sint.