Escalab 250xi k alpha

The morphology of the prepared samples was observed by scanning electron microscopy (SEM, Quanta FEG 250). The crystal structure of the composites was characterized by powder X-ray diffraction (XRD, X'Pert Pro MPD) using Cu-Kα radiation (λ = 0.15404 nm). The data was collected under a continuous scan mode between 10 and 90° with a step size of 0.02° and a scan rate of 2° min⁻¹. The current and voltage were set at 30 mA and 40 kV, respectively. The Brunauer–Emmett–Teller (BET) specific surface areas of as-prepared samples were measured by N₂ adsorption–desorption isotherm with a Quantachrome NOVA touch LX4 apparatus (Quantachrome Autosorb-IQ, USA). The chemical compositions and bonds were studied by X-ray photoelectron spectroscopy (XPS, ESCALAB 250Xi K-alpha, Thermo Fisher Scientific) with Al Kα X-ray at 15 kV and 150 W. Fourier transform infrared (FTIR) spectra were measured by using a VERTEX70 spectrometer. Thermogravimetric analysis (TGA; Mettler-Toledo) was performed using a simultaneous differential thermal analysis (DTA). A heating rate of 5 °C min⁻¹ was used from room temperature to 900 °C under atmospheric air. Vibrating sample magnetometer (VSM) (Model: Lake shore 7400, United States) was employed to study the hysteresis loops and the magnetic properties of the magnetite nanocomposites.