Effects of hydrogen annealing and codoping (Mn, Fe, Ni, Ga, Y) of nanocrystalline Cu-doped ZnO dilute magnetic semiconductor

Abstract

Zinc oxide (ZnO) codoped with Cu and M ions (M = Mn, Fe, Ni, Ga, Y) powders were synthesised by simultaneous thermal co-decomposition of a mixture of zinc and metal complexes. The synthesised chemical formula for the prepared solid solution is Zn 0.97 Cu 0.01 M 0.02 O. X-ray diffraction (XRD) analysis confirms the formation of single nanocrystalline structure of the as-prepared powders, thus, both Cu and M ions were incorporated into ZnO lattice forming solid solutions. Magnetic measurements reveal that all the as-synthesised doped ZnO powders gained partial (RT-FM) properties but with different strength and BH-behaviour depends on the nature of the doping (M). Furthermore, H 2 post-treatment was subsequently carried out and it was found that the observed RT-FM is enhanced. Very interestingly, in case of Ni dopant, the whole powder becomes completely ferromagnetic with coercivity (H c ), remanence (M r ) and saturation magnetisation (M s ) of 133.6 Oe, 1.086 memu/g and 4.959 memu/g, respectively. The value of Ms was increased by ~ 95% in comparison with as-prepared.