Optical and magnetic properties of Zn0.98Mn0.02O nanoparticles

Pure and Mn-doped colloidal ZnO particles were prepared in a solvo-thermal via sol-gel process by base-catalyzed hydrolysis of zinc acetate. We have studied the structural, magnetic and optical properties of the samples using X-ray diffraction (XRD), transmission electron microscopy, energy dispersive X-ray analysis, superconducting quantum interferometer device and UV-Vis spectroscopy. The XRD spectra show that all the samples are hexagonal wurtzite structures. The calculated average particle size of the samples was approximately 7-3 nm, indicating that the particle size decreased by doping with manganese. Magnetic investigations showed that at room temperature the Mn-doped ZnO possessed ferromagnetism with the saturation magnetic moment of 0.194 emu/g. The room temperature PL measurements illustrate UV-emission centered at 351 nm (3.53 eV), which is ascribed to the near-band-edge emissions of ZnO, violet emission at 512 nm (2.42 eV). The UV-Vis spectra showed a blue-shift from 3.42 to 3.78 eV when the ZnO doped with manganese.