Cobalt-doped ZnO powder samples were prepared by sol-gel and hydrothermal method combined.The prepared powder samples were characterized by X-ray diffraction（XRD）,scanning electron microscopy（SEM）,electron paramag...Cobalt-doped ZnO powder samples were prepared by sol-gel and hydrothermal method combined.The prepared powder samples were characterized by X-ray diffraction（XRD）,scanning electron microscopy（SEM）,electron paramagnetic resonance（EPR） and vibrating sample magnetometry（VSM）.XRD patterns show that all the samples have a single pure phase with wurtzite structure suggesting that Co2＋ occupied Zn2＋ sites in the ZnO crystal lattice.SEM images show that crystal grains of cobalt-doped ZnO are hexagonal cone or spheroidal.EPR pattern shows that all of the samples possess oxygen vacancy.Measurement of magnetism indicates that all the samples exhibit room temperature ferromagnetism（RTFM） embedded in a dominant diamagnetic or paramagnetic signal.The dominant signal turns from diamagnetic to paramagnetic with the increase of Co concentration.The magnetic behavior can attribute to defects and Co doping.展开更多
基金Project supported by the 46th Institute of China Electronics Technology Group Corporation(No.0231182346)
文摘Cobalt-doped ZnO powder samples were prepared by sol-gel and hydrothermal method combined.The prepared powder samples were characterized by X-ray diffraction（XRD）,scanning electron microscopy（SEM）,electron paramagnetic resonance（EPR） and vibrating sample magnetometry（VSM）.XRD patterns show that all the samples have a single pure phase with wurtzite structure suggesting that Co2＋ occupied Zn2＋ sites in the ZnO crystal lattice.SEM images show that crystal grains of cobalt-doped ZnO are hexagonal cone or spheroidal.EPR pattern shows that all of the samples possess oxygen vacancy.Measurement of magnetism indicates that all the samples exhibit room temperature ferromagnetism（RTFM） embedded in a dominant diamagnetic or paramagnetic signal.The dominant signal turns from diamagnetic to paramagnetic with the increase of Co concentration.The magnetic behavior can attribute to defects and Co doping.
