衬底温度对脉冲激光沉积在Si衬底上Zn_(0.95)Co_(0.05)O薄膜的影响

Effect of growth temperature on the Zn_(0.95) Co_(0.05) O films on Si substrate prepared by pulsed laser deposition

在不同的衬底温度下在n型Si(111)衬底上采用脉冲激光沉积的方法生长了(002)择优取向的具有室温铁磁性的Zn0.95Co0.05O薄膜。X射线衍射显示所生长的薄膜呈六方纤锌矿结构。X射线光电子能谱测试表明薄膜中出现的室温铁磁性不是由于Co团簇产生的。发现薄膜生长过程中产生的间隙锌、氧空位以及晶格缺陷对铁磁性有显著的影响。通过改变衬底温度可以控制薄膜中间隙锌、氧空位及晶格缺陷的数量,薄膜的铁磁性同时也可以被明显地改变,这是缺陷与薄膜的室温铁磁性相关的直接证据。

Room-temperature ferromagnetic Zn0.95Co0.05O thin film with （002） preferential orientation were grown by pulsed laser deposition at different substrate temperature on n-type Si（lll） substrate. X-ray diffrac- tion shows that the growth of thin film was hexagonal wurtzite structure. X-ray photoelectron spectroscopy re- sults indicate that this ferromagnetic behavior is not due to Co microclusters in the film. Zinc interstitials, oxy- gen vacancies and lattice defects induced by low substrate deposition temperature show significant effect on the ferromagnetic behavior. By changing the substrate temperature to control the amount of zinc interstitials, oxy- gen vacancies and lattice defects, the ferromagnetism can be tuned significantly as well, which provides a direct evidence that these defects contributed to the ferromagnetism in ZnCoO thin film.