Study of Co and Fe-doped ZnO milled nanopowders

Abstract

Fe and Co-doped ZnO powders obtained by mechanical milling from different starting materials are presented. Both the local structural and the magnetic properties are investigated using X-ray diffraction, XAFS and magnetic measurements. The evolution of these properties with milling time, atomic content and milling atmosphere is analyzed. XAFS measurements revealed the progressive incorporation of doped atoms into the ZnO wurtzite crystalline structure. Also, the oxidation states of 2+ and 3+ for Fe atoms and 2+ for Co ones are confirmed. Furthermore, the presence of oxygen vacancies is predicted by EDAX and XAFS. These results, in combination with previous ones, will contribute to the comprehension of the controversial ferromagnetic behavior in these diluted semiconductor materials.