Structural, Optical and Magnetic Properties of (Al, Ni) Co-Doped ZnO Nanoparticles

In the present work, the synthesis of Zn0.9-xNi0.1AlxO (x = 0.01, 0.015, 0.02 and 0.025) nanoparticles by sol-gel and theirs structural, optical and magnetic properties were investigated. In our approach, we performed a drying under supercritical conditions of ethyl alcohol. An esterification reaction was established to release water slowly. The powder obtained underwent a heat treatment in air at 500 degrees C in 2 hours. The results obtained by X-rays diffraction (XRD) and transmission electronic microscopy (TEM) showed that the structure is wurtzite with a crystallite size ranging from 25 nm to 40 nm, and a second phase was detected, linked to the NiO phase. Ultraviolet-visible (UV-Vis) spectroscopy shows a decrease in bandgap values with increasing of Al concentration. Photoluminescence (PL) results indicate the effects of oxygen vacancies on emission spectra. Magnetic measurements at 300 K and 10 K showed a paramagnetic with an improve of ferromagnetic at low temperature.