Colloidal Fe-doped ZnO nanocrystals: Facile low temperature synthesis, characterization and properties

Colloidal Fe-doped ZnO nanocrystals, Zn1−xFexO (x = 0.00, 0.05, 0.07 and 0.1) have been prepared by thermal decomposition of metal precursors at 200 °C with hexadecylamine (HDA) as solvent and surfactant. The nanocrystals so prepared can be easily dispersed in non-polar solvents like chloroform and toluene. The nanocrystals have been structurally characterized using X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM), energy dispersive X-ray analysis (EDX) and X-ray photoelectron spectroscopy (XPS). Magnetization measurements on a representative sample, Zn0.95Fe0.05O using a vibrating sample magnetometer (VSM) reveal that the nanocrystals exhibit a weak ferromagnetic behavior at 300 K. This observation is further confirmed by the electron paramagnetic resonance spectrum of Zn0.95Fe0.05O nanocrystals, which shows a distinct ferromagnetic resonance signal at room temperature.