Structure and Magnetic Properties of Co-doped ZnO Powder Prepared by Sol-gel Method

摘要

Un-doped and 5% Co-doped ZnO powders were prepared by sol-gel method using Zn(CH_3COOH)_2.2H_2O and Co(CH_3COOH)_2.2H_2O as starting precursors and ethanol as a solvent, the powders were heated at 550°C for 30 minute in air. In this paper, using methods such as X-Ray diffraction (XRD), Raman and vibrating sample magnetometer (VSM), we have compared un-doped and 5% Co-doped ZnO powder to study the structure and magnetic properties of Co-doped ZnO powder. The XRD patterns of 5% Co-doped ZnO powder showed that no second phase appeared and no change for the wurtzite structure of ZnO, which indicated that Co ions are substituted for Zn ions. Raman spectra of 5% Co-doped ZnO powder showed that there was an additional frequency at 543 cm~(-1), which was assigned as Co-O mode. The VSM showed that 5% Co-doped ZnO powder had ferromagnetic properties at room temperature with the coercive field (H_c) about 90 Oe.