共沉淀法制备Co掺杂ZnO的室温铁磁性的研究

利用共沉淀法并在5vol.%H₂/Ar气流中于300 ℃退火3 h，制备了Zn_1-xCo_xO稀磁半导体. 扫描电子微探针分析表明，对Co的名义组分分别为0.05，0.10，0.15的样品，其实际组分分别为x＝0.054， 0.100和0.159. X射线衍射表明, 主相为纤锌矿结构, x=0.100和 0.159的样品中含有CoO杂相. X射线光电子谱显示出Co有３种状态: 替代进入Z 关键词： 稀磁半导体 ZnO 共沉淀法 磁性来源

Room-temperature ferromagnetism in Co-doped ZnO fabricated by coprecipitation method

Nanocrystalline Zn_1-xCo_xO samples were prepared by coprecipitation and annealing at 300 ℃ for 3 h in 5vol.%H₂/Ar flow. Scanning electron microprobe measurements indicate that the samples with nominal Co contents of 0.05, 0.10, and 0.15 have the actual Co contents of 0.054, 0.100, and 0.159 respectively. X-ray diffraction patterns show that the major phase of the samples is of wurtzite structure, while the minor phase of CoO is observed in samples with Co contents of x=0.100 and 0.159. X-ray photoelectron spectroscopy shows that Co has three states: Co incorporated into ZnO matrix, CoO and metallic Co. It was found through magnetic measurements, that room-temperature ferromagnetism exists in all the samples and it comes from both the weak ferromagnetism of Zn-doped CoO_1-δ and the magnetism of metallic Co clusters.