AbstractPure cubic phase, In2O3 nanoparticles with porous structure were synthesized by solid state thermal oxidation of un-irradiated and γ-irradiated indium acetyl acetonate in presence and absence of sodium dodecyl sulphate as surfactant. The as- synthesized In2O3nanoparticles were characterized by X-ray diffraction (XRD), fourier transformation infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transition electron microscopy (TEM) and thermogravimetry (TG). The shapes and morphologies of as- synthesized In2O3nanoparticles were highly affected by γ-irradiation of indium acetyl acetonate precursor and by addition of sodium dodecyl sulphate as surfactant. Calcination of un-irradiated indium acetyl acetonate precursor to 4 hours of 600 °C leads to the formation of spherical- shaped accumulative and merged In2O3 nanoparticles with porous structure, whereas irregular porous architectures composed of pure In2O3nanoparticles were obtained by using γ-irradiated indium acetylacetonate precursor. The as- prepared In2O3 nanoproducts exhibit photoluminescence emission (PL) property and display thermal stability in a wide range of temperature (25-800 °C) which suggest possible applications in nanoscale optoelectronic devices.

Pure phase of In2O3 nanoparticles were synthesized by sol-gel method in non-aqueous medium using un-irradiated and γ-irradiated indium acetate precursors. The as-prepared In2O3 nanoparticles were characterized by XRD, FT-IR, SEM, TEM and TG techniques. The results showed that pre-irradiation to indium acetate with 10² KGy γ-ray absorbed dose has significant effects on the shape and size of the as-synthesized In2O3 nanoparticles. In case of un-irradiated precursor, the SEM images show agglomerated and disordered spherical nanoparticles. In γ-irradiated case the particles showed coral-like structure. The as-synthesized In2O3 nanoparticles prepared using γ-irradiated precursor showed higher thermal stability compared with those prepared using un-irradiated one. The results were discussed in view of the role of γ-irradiation on the morphology and thermal behavior of In2O3 nanoparticles.

Kinetic studies for the non-isothermal decomposition of un-irradiated and γ-irradiated indium acetyl acetonate In(acac)3 with 10² kGy total γ-ray dose were carried out in static air. The results showed that the decomposition proceeds in one major step in the temperature range of 150-250 °C with the formation of In2O3 as solid residue. The non-isothermal data for un-irradiated and γ-irradiated In(acac)3 were analysed using linear Flynn-Wall-Ozawa (FWO) and nonlinear Vyazovkin (VYZ) iso-conversional methods. The results of application of these free models on the investigated data showed a systematic dependence of Ea on α indicating a simple decomposition process. No significant changes were observed in both decomposition behaviour and (Eα-α) dependency between unirradiated and γ-irradiated In(acac)3. Calcination of In(acac)3 at 400 °C for 5 hours led to the formation of In2O3 monodispersed nanoparticles. X-ray diffraction, FTIR and SEM techniques were employed for characterization of the synthesised nanoparticles. This is the first attempt to prepare In2O3 nanoparticles by solid state thermal decomposition of In(acac)3.