基片温度对Co掺杂ZnO薄膜室温铁磁性的影响(英文)

The Effect of Substrate Temperature on the Room Temperature Ferromagnetism of Co-Doped ZnO Thin Films

采用磁控共溅射法在Al2O3（0001）基片上沉积了Zn1-xCoxO（x=0.08～0.31%）薄膜,研究了基片温度对Co掺杂ZnO薄膜结构和磁性的影响。结果表明：Al2O3（001）基片很好地诱导了ZnCoO薄膜（002）取向生长,并且所有的薄膜均显示室温铁磁性。较低的基片温度不仅能有效抑制薄膜中Co2O3杂质相的产生,而且薄膜磁矩较大。紫外-可见光谱也表明,薄膜中Co^2＋取代了ZnO中Zn^2＋的位置。

Zn1-xCoxO （x=0.08～0.31） thin films were prepared on c-cut sapphire substrates by magnetron co-sputtering. The effects of substrate temperatures on the structures and magnetic properties of Co-doping ZnO thin films were investigated. The results indicate that c-cut sapphire substrates induce highly （002） oriented growth of ZnCoO films. And all films show room temperature ferromagnetism. Moreover, the low substrate temperature can not only hinder the generation of the second Co2O3 phase, but also remarkably enhance the ferromagnetism of ZnCoO film compared with high substrate temperature. Optical spectrometry indicates that Co^2＋ enters the tetrahedral sites of the wurtzite structure of ZnO host and substitutes for Zn^2＋.