The Structure Research of Co Ions Implanted in Single Crystal ZnO

At room temperature, single-crystal ZnO was implanted with Co ions at an energy of 80 keV using fluence of 1 x 10(17) ions.cm(-2). The samples were heat treated by conventional thermal annealing at 700 degrees C for 10 min. The structural properties were investigated of all samples by means of X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Extended X-ray absorption fine structure (EXAFS). XRD analysis indicates that there are Co or CoO nanoparticles in the samples before and after annealed. The peak of ZnO(002) shifts to larger angle presumably results from the Co(2+) ions substituting for a part of Zn(2+) ions in the ZnO lattice. Ion implantation without changing the lattice structure of ZnO. The XPS results indicate that Co element in the ZnO mainly exists in the form of Co(2+), the reason may be that Co ions combine with O element in ZnO as oxide or Co ions substitute for Zn(2+) sites in the ZnO. EXAFS analyses provide that Co ions mainly exist as Co nanoparticles in the samples.