Abstract
Defect engineering techniques have been employed to generate and remove oxygen vacancy defects in nanoparticles of Y 2 O 3 :Mn diluted magnetic oxide (DMO). These samples were prepared by thermal decomposition method followed by a series of thermal annealing in oxygen and forming gas. The x-ray absorption analysis reveals that O vacancies surrounding Mn and Y atoms were appreciably increased by forming-gas-annealing and decreased by oxygen-annealing, accompanied by enhanced and reduced saturation magnetization as demonstrated by magnetic measurements, respectively. Our results demonstrate strong correlation between magnetism and O vacancies and therefore strongly support the bound magnetic polaron model for these high-k DMOs. © 2012 American Institute of Physics.