Impact of Al3+ Substitution on Features of Structural Properties in Nanosized Spinel Copper Ferrites

Nanosized spinel ferrites CuAlxFe2-xO4 (where x=0.0, 0.2, 0.4, and 0.6) nanoparticles have been synthesized using the citrate-nitrate auto-combustion technique. The crystal structure's properties of the synthesized nanoparticles have been determined through X-ray diffraction (XRD) and Fourier transform infrared (FTIR) analyses. The extracted XRD data has demonstrated that all samples have a single phase with no undesirable impurities or phases. The samples of (x=0.0 and x=0.2) have a tetragonal structure while the samples of (x=0.4, 0.6) have a cubic spinel structure. The average crystallite size of the nanoparticles is found to be in the accepted nano-size range. The lattice parameter behavior of the tetragonal and cubic samples correlates well with the Jahn-Teller effect and Vegard's law respectively. The atomic defects like dislocation density (δ) and strain (ε) increase with increasing the Al3+ concentration and have an inverse behavior of the crystallite size as expected. Also, the formation of Cu-Al ferrite samples has been confirmed by two prominent absorption bands (υ1 and υ2) at approximately 592 cm-1 and 410 cm-1 respectively.