(Fe, Nd) codoped ZnO micro– and nanostructures with multifunctional characteristics like photocatalytic activity, optical and ferromagnetic properties

Abstract

Zn1-x-yFexNdyO, x = 0.02 and y = 0.00–0.05 were successfully synthesized via a hydrothermal method at 200 °C. XRD and Mössbauer spectroscopy indicated that (Fe, Nd) codoped ZnO, calcined at 700 °C, 3 h in air, contains hexagonal ZnO phase as main phase and traces of ZnFe2O4; no phase containing neodymium was observed. In this study, a strong powder morphology dependence on Nd concentration and calcination temperature was evidenced by SEM. The photocatalytic properties were found to depend on the sample morphology and Nd content. Thermoluminescence signal is weak compared to the undoped ZnO and the curves shape was almost independent on the doping level and dependent on the calcination temperature and was related to the structural defects induced by the synthesis and calcination. Photoluminescence spectra showed that the green-yellow band due to the oxygen related defects, decreases by Fe and Nd-codoping. Thermo-magnetization curves measured in low applied fields and the magnetic hysteresis loops recorded in the temperature range 5–380 K, indicate two superimposed magnetic regimes, one predominant above 100 K the other below 100 K. The observed magnetic order is not directly related to the dopant Fe or Nd ions, but to different type of defects.