Vacuum Sol-Gel Synthesis and Characterization of NiAl2O4 Nanoparticles
Nowadays, there is a big interest in the preparation of mixed oxides with transition metal atoms. Spinel oxides of AB2O4 formula present structural properties that make them attractive in magnetic applications, sensor technology and refractory materials . The nickel aluminate structure NiAl2O4, makes it resistant to acids and alkalis, presents high melting point and surface area, extraordinary catalytic properties and is resistant to deactivation by coke formation . Those properties allow a wide use in the oil industry in processes as hydrogenation, methanation and steam reforming [3, 4]; this material is also employed in high temperature fuel cells and as an anode for the production of aluminum . In this work, we report the production of nickel aluminate nanoparticles (NiAl2O4) with a considerable magnetic field of 137.09 Oe by employing a -300 Hg mm vacuum sol-gel chemical synthesis. The material was evaluated through Differential Scanning Calorimetry, Thermogravimetric analysis (DSC/TGA), Fourier Transform Infrared spectroscopy (FTIR), X-Ray Diffraction analysis (XRD), Scanning Electron Microscopy (SEM), high resolution Transmission Electron Microscopy (HR-TEM) analysis and its magnetic behavior was corroborated by a vibrating sample magnetometer (VSM). Preliminary results show the formation of NiAl2O4 nanocrystals with dimension of 5 to 15 nanometers, homogeneous morphology, inverse spinel structure and weak ferromagnetic behavior with a coercive field (Hc) of 66.29 Oe, a remainder magnetization (Mr) of 7.15 emu/g and a saturation magnetization (Ms) of 71.34 emu/g.