Magnetic and structural properties basic solid state physics of transition metal doped zinc-oxide nanostructures

We report on the magnetic and structural properties of two types of nanostructures doped with Co or Mn, namely, ZnO nanowires and colloidal ZnO nanocrystals. Electron paramagnetic resonance (EPR) spectra have been measured and analysed to extract information on the incorporation of the ions in the lattice. A detailed analysis by means of simulations of the experimental EPR spectra confirms that the transition metal (TM) ions were mainly incorporated as TM2+, occupying the Zn2+ sites in the wurtzite structure of ZnO. Furthermore, for both types of nanostructures, the EPR spectra are composed of more than one signal, revealing locally distorted environments or core-shell structures, proved by surface modifications via inorganic coatings