溶胶-凝胶法制备Co掺杂ZnO薄膜及其室温铁磁性(英文)

ROOM TEMPERATURE FERROMAGNETISM OF Co-DOPED ZnO FILMS PREPARED BY SOL-GEL METHOD

以聚乙烯醇为溶剂,用溶胶-凝胶法在石英玻璃基底表面制备了Zn1-xCoxO(x=0.08,0.10,0.12)稀磁半导体薄膜。研究表明:Zn1-xCoxO薄膜均为纤锌矿结构,没有出现与Co相关的杂质相,Co2+取代Zn2+位置进入ZnO的晶格,样品的光学带隙随Co含量的增加而减小。Zn1-xCoxO稀磁半导体薄膜具有室温铁磁性,其饱和磁化强度(Ms)和矫顽力(Hc)均随Co2+含量(x=0.08,0.10,0.12)的增加而逐渐增大,Ms分别为1.12×104,1.45×104A/m和1.66×104A/m,Hc分别约为2.31×105,3.30×105A/m和4.26×105A/m,并讨论了其铁磁性的来源。

Zn1-xCoxO （x = 0.08,0.10 and 0.12） thin films were prepared on the surface of quartz glass substrates by sol-gel method using polyvinyl alcohol aqueous solution as the solvent. The results show all films are ZnO wurtzite without impurity phases,and the doped Co2＋ partially substitutes Zn2＋ in ZnO lattice. The optical band gap of the films becomes narrower,and shows a redshift with increasing x. Magnetic properties measurements reveal that all the films are ferromagnetism at room temperature. With the increase of Co2＋ content the saturation magnetization （Ms） and coercivity field （Hc） of the film increase. For x = 0.08,0.10 and 0.12,Ms of these films is 1.12 × 10^4,1.45 × 10^4 and 1.66 × 10^4 A /m respectively,and Hc is about 2.31 × 10^5,3.30 × 105 and 4.26 × 105 A/m,respectively. The origin of ferromagnetism in Co-doped ZnO films is also discussed.