Structural, dielectric and magnetic properties of (Al, Ni) co-doped ZnO nanoparticles

A highly valuable co-precipitation technique was used for the preparation of ZnO, Zn0.98Al0.02O and Zn0.96Al0.02Ni0.02O semiconductor nanoparticles. X-ray diffraction and scanning electron microscopy measurements reveal that the samples are nano-columns with a hexagonal wurtzite crystal structure. A significant enhancement in dielectric constant resulted from the substitution of (Al, Ni) co-doped ZnO lattice while an opposite trend was observed for dielectric loss. With the substitution of both Al and Ni, the electrical conductivity was found to be increased in comparison with that of ZnO nanoparticles due to the increase of available charge carriers after replacement of Zn ions by Ni ions. The magnetic property measurements revealed well room-temperature ferromagnetism, RTFM (Diluted magnetic semiconductor behavior) for the Ni co-doped samples in comparison with that of single Al-ZnO. The origin of high ferromagnetic may arise from the metallic Ni and intrinsic property of the doped ZnO.