Crystallographic, morphological, optical and magnetic characterization of transition metal and rare earth elements doped one dimensional ZnO nanostructures

Nanorods as one-dimensional ZnO semiconductor structures were produced via hydrothermal method. Crystal structure, elemental distribution, morphological properties, optical and magnetic behavior of all samples were characterized by XRD, SEM, EDX, AFM, UV-Vis spectrophotometer, fluorescence spectrophotometer and VSM. The effects of crucial production parameters such as hydrothermal synthesis time and temperature on the undoped ZnO nanorods were investigated in detail. ZnO nanorods were synthesized at different synthesis times (2, 3, 4 and 5 hours) and temperatures (70, 90, 120, 150 oC). ZnO nanorods were successfully grown perpendicular to the glass substrate. Nevertheless, at the temperature of 70 oC, no crystal growth was observed. It is concluded that the temperature of 70 oC could not provide the appropriate reaction conditions for ZnO nanorod synthesis. In addition, it was found that the synthesis time and temperature has a significant effect on both structural and optical properties of ZnO nanorods. From this point of view, by changing the production parameters, it was seen that the nanorods' morphological properties including diameter, length and shape could be adjusted as well as the optical properties including transmittance and band gap. Fe as transition metal, Nd and Eu as earth elements were doped to ZnO. The samples of Zn1-xFexO, Zn1-xEuxO, Zn1-xNdxO (x= 0,01; 0,03; 0,05 ve 0,07) were obtained. The absence of any secondary phase in X-ray diffraction patterns showed that all the doping elements were successfully incorporated into ZnO crystal structure. An improvement was observed in the structural and optical properties of doped ZnO nanorods. While ZnO exhibited diamagnetic behavior at room temperature, all the doped samples exhibited ferromagnetic behavior. Here, it can be concluded that Fe, Nd and Eu doped ZnO nanorods can be suitable candidates for spintronic applications.