Crystallographically oriented magnetic ZnFe2O4 nanoparticles synthesized   by Fe implantation into ZnO
  In this paper, a correlation between structural and magnetic properties of Fe implanted ZnO is presented. High fluence Fe^+ implantation into ZnO leads to the formation of superparamagnetic alpha-Fe nanoparticles. High vacuum annealing at 823 K results in the growth of alpha-Fe particles, but the annealing at 1073 K oxidized the majority of the Fe nanoparticles. After a long term annealing at 1073 K, crystallographically oriented ZnFe2O4 nanoparticles were formed inside ZnO with the orientation relationship of ZnFe2O4(111)[110]//ZnO(0001)[1120]. These ZnFe2O4 nanoparticles show a hysteretic behavior upon magnetization reversal at 5 K. 
Shengqiang Zhou, K. Potzger, H. Reuther, G. Talut, F. Eichhorn, J. von   Borany, W. Skorupa, M. Helm and J. Fassbender