Structural properties of some nanocrystalline spinel chromites prepared by solid-state reaction method
Chromium nanocomposites MCr2O4 have been synthesized by a solid-state reaction. The synthesized samples were characterized using X-ray powder diffraction technology (XRD). The temperature of synthesis was 1000 °C for NiCr2O4 and 900 °C for Zn Cr2O4. Miller indices (hkl) were calculated for the production, and the compounds were shown to have cubic structure FCC. The lattice parameters were as follows: a = 8.26 Å, Z = 8, V = 564.26Å3 and a = 8.2650 Å, Z = 8, V = 564.58 Å3 for NiCr2O4 and ZnCr2O4 respectively. The space group of symmetry is Fd3m for the both. The grain sizes were calculated by the Debye — Scherrer formula for the two compounds and were 31.92 nm and 32.78 nm, respectively. The ZnCr2O4 and NiCr2O4 nanoparticles' morphology was examined using scanning electron microscopy (SEM). The SEM images showed the agglomeration of the nanoparticles, which were formed of square-shaped nanocrystallites.