A new combustion route for the synthesis of 𝛾-Fe₂O₃ is reported by employing purified 𝛼-Fe₂O₃ as aprecursor in the present investigation. This synthesis which is similar to a self propagation combustion reaction, involves fewer steps, a shorter overall processing time, is a low energy reaction without the need of any explosives, and also the reaction is completed in a single step yielding magnetic iron oxide i.e. 𝛾-Fe₂O₃. The as synthesized 𝛾-Fe₂O₃ is characterized employing thermal, XRD, SEM, magnetic hysteresis, and density measurements. The effect of ball-milling on magnetic properties is also presented.

This paper reports the electrical and spectroscopic investigation of the gamma ferrite synthesized through combustion route. The electrical study and dielectric behaviour showed a typical ferrite nature for the samples. The $\gamma \rightarrow \alpha $ transition is observed from the electrical conductivity data. Infrared spectral study showed the transition of a typical ferrite. The effect of the presence of 𝛼-impurities in 𝛾-Fe₂O₃ is also explained here.

Novel combustion synthetic route for the synthesis of nanosized SnO₂ is reported. X-ray, tap and powder densities of SnO₂ are calculated. Adsorption of Pb²⁺ ions on combustion derived nanosized SnO₂ is studied. The as synthesized SnO₂ and lead ions adsorbed SnO₂ are characterized by X-ray diffraction (XRD), scanning electron micrograph (SEM), and infrared spectroscopic (IR) techniques. The eluent is characterized by atomic absorption spectroscopy (AAS) and solution conductivity (SC) to know the reduction in the concentration and increase in conductance of lead solution after adsorption on the SnO₂ surface. The potential use of solid adsorbents for the adsorption of heavy metal pollutants is envisaged in the present work.

The synthesis of ultrafine MoO₃ through a self-propagating combustion route employing polyethylene glycol as fuel is reported. The precursor molybdenum oxalate is employed in this study for the conversion of the precursor to ultrafine MoO₃ particles. The solvent casting method is adopted for the synthesis of MoO₃ dispersed polyvinyl alcohol nanostructured film (MoO₃–PVA). These synthesized MoO₃ and their composite samples are characterized for their structure, morphology, bonding and thermal behaviour by XRD, SEM, IR and DSC techniques, respectively. The distribution of MoO₃ in polyvinyl alcohol gives a crystalline polymer, a compact structure and an increase in glass transition temperature.

Solid adsorbents have shown great promise for control of particulate and non-particulate matter and as gas sensing devices in recent times. In the present study, adsorption of environmental toxic pollutant such as lead ions on solid adsorbents viz. 𝛼-Fe₂O₃ and fly ash, are reported. Considerable adsorption was observed on fly ash when compared to 𝛼-Fe₂O₃ surface. These studies are characterized by employing solid state and solution studies.

New combustion synthetic route for the synthesis of nanosized 𝛾-Fe₂O₃ by microwave-assisted route is reported. X-ray density, tap density and powder density of prepared 𝛾-Fe₂O₃ are calculated. Adsorption study of Pb²⁺ on combustion derived nanosized 𝛾-Fe₂O₃ is studied by dynamic method. The 𝛾-Fe₂O₃ structure and lead adsorbed 𝛾-Fe₂O₃ (Pb-𝛾-Fe₂O₃) are studied by X-ray diffraction (XRD). Additional lead peaks in Pb-𝛾-Fe₂O₃ sample pattern confirm the lead adsorption. Morphology of as prepared 𝛾-Fe₂O₃ and Pb-𝛾-Fe₂O₃ is studied by scanning electron micrograph (SEM) technique. Varied morphology for Pb-𝛾-Fe₂O₃ compared to its 𝛾-Fe₂O₃ is observed. Variation of bonding in Pb-𝛾-Fe₂O₃ sample due to lead adsorption is viewed by infrared spectroscopic (IR) technique. Energy dispersive X-ray microanalysis (EDX) is scanned for the lead adsorbed 𝛾-Fe₂O₃ to know the presence of lead on 𝛾-Fe₂O₃ surface. The eluent lead solution is characterized by atomic absorption spectroscopy (AAS) and solution conductivity (SC). Reduction in the concentration and increase in conductance of eluent lead solution is observed. The potential use of solid adsorbents for the adsorption of heavy metal pollutants is envisaged in the present work.

Nanometer-sized 𝛼-Fe₂O₃ particles have been prepared by a simple solvothermal method using ferric acetylacetonate as a precursor. The products were characterized by X-ray diffraction (XRD), energy dispersive X-ray microanalysis (EDAX), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transition electron microscopy (TEM), infrared spectroscopy (IR) and thermal analysis (TG–DTA). XRD indicates that the product is single-phase 𝛼-Fe₂O₃ with rhombohedral structure. Bundles of acicular shaped nanoparticles are seen in TEM images with an aspect ratio ∼ 12; typically 8–12 nm wide and over 150 nm long. The 𝛼-Fe₂O₃ nanoparticles posses a high thermal stability, as observed on thermal analysis traces.

The barium ferrite particles were prepared using a self-propagating low-temperature combustion method using polyethylene glycol (PEG) as a fuel. The process was investigated with simultaneous thermogravimetric-differential thermal analysis (TG–DTA). The crystalline structure, morphology and the magnetic properties of the barium ferrite particles were studied by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and SQUID susceptometer. The results show that the ignition temperature of PEG is lower compared with other combustion methods and gives nanocrystalline barium ferrite.

The self-propagating low-temperature combustion method was used to produce nanocrystalline particles of zinc ferrite. The products were characterized for chemical and phase composition, morphology and magnetic properties. The results obtained showed the formation of single-phase zinc ferrite nanoparticles with an average particle size of about 40 nm. As-synthesized powder displayed good magnetic property. Due to the simplicity and low cost of this process, it could also become a valuable starting point for the generation of other mixed and complex ferrites.