Investigation of structural and magnetic properties of transition metal Dy substituted Zn0.80-4yDyyOx compounds

In this study, Zn0.80-4yDyyOx (0.05 ? y ? 0.10) diluted magnetic semiconductors were synthesized by the solid state reaction method. The structural and magnetic properties of the samples have been studied by using the X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Energy Dispersive X-Ray spectroscopy (EDX), Hysteresis, Magnetization and A.C. Susceptibility techniques. The SEM results clearly demonstrate that Dy ions integrate into the ZnO structure without any problem. The grains of the samples are very well connected to each other and tightly packed. From the XRD and EDX spectra of the samples, it has been concluded that the doping causes no change in the hexagonal wurtzite structure of ZnO. Paramagnetism has been observed for all the samples at temperatures between 10 K and 300 K. Magnetizations increase gradually with increasing Dy concentration; indicating that the doping of Dy in ZnO causes a paramagnetic contribution, increasing with Dy amount. The trend of the A.C-susceptibility (?) versus temperature curves, measured under an A.C-magnetic field of 10 Oe, also support our conclusion about the paramagnetic contribution. But, from the temperature variations of the inverse magnetic susceptibility of all the samples, a typical Curie-Weiss behavior is observed. The fit of the linear portion to the Curie-Weiss relation of the curves give negative Weiss temperature (Q). The negative values of Q indicate antiferromagnetic interactions in the Dy substituted samples. However, the antiferromagnetic interactions decrease gradually with increasing Dy concentration.