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Electron spin resonance in situ was applied to study the initial stages of ferrofluid formation in combination with the X-ray diffraction, high-resolution transmission electron microscopy and Fourier transform infrared spectroscopy studies data. The ultrafine (d = 4 nm) magnetite in dimethylsulfoxide ferrofluid with a narrow size nanoparticles distribution was obtained in a single step at room temperature by admixing butylene oxide to a solution of iron (II) and (III) chlorides in dimethylsulfoxide. It has been shown that at the first step of the ferrofluid synthesis antiferromagnetically ordered iron containing phase is formed, which can be correlated with iron hydroxides. [ABSTRACT FROM AUTHOR]

The stability of a catalyst for partial H2S oxidation has been studied by the ferromagnetic resonance (FMR) technique combined with transmission electron microscopy, X-ray diffraction, Mössbauer spectroscopy, and magnetostatic investigations. The ε-Fe2O3 iron oxide nanoparticles supported on silica have been examined for their stability under the selective H2S oxidation conditions. The combination of the physicochemical methods has been used to study the state of reacted catalysts. The ε-Fe2O3 phase has been found to remain stable under the selective H2S oxidation conditions at temperatures up to 300 °C. The active phase state during the catalytic reaction has been explored using in situ FMR experiments. It has been established that the ε-Fe2O3 nanoparticles retain their structure and magnetic properties in the presence of H2S at high temperatures. During the in situ FMR experiments, the ε-Fe2O3 sulfidation process has been studied. [ABSTRACT FROM AUTHOR]