热处理对稀磁半导体Al_(1-x)Cu_xN薄膜性能的影响

Effect of Heat Treatment on the Properties of Diluted Magnetic Semiconductor Al_(1-x)Cu_xN Thin Film

采用磁控溅射法,在蓝宝石衬底上沉积Al1-xCuxN薄膜样品,并对样品进行退火处理。利用X-射线衍射仪和超导量子干涉仪分别研究了退火前后薄膜的结构和磁性能。研究发现退火处理工艺有效地改善了样品的结晶特性和铁磁性:Al1-xCuxN从非晶薄膜转变为多晶薄膜;950℃、氮气气氛退火处理后样品的最大饱和磁矩增加到原来的两倍,约为5.16 emu/cm3。结合X射线光电子能谱和光致发光性能分析,Al1-xCuxN铁磁性来源于Cu原子与其最近邻的N原子之间的p-d杂化和N原子周围缺陷位置极化共同作用。

Al1-xCuxN thin films were prepared on sapphire substrate by magnetron sputtering technique.The effects of heat treatment on structural and ferromagnetic properties of Al1-xCuxN thin films were studied by X-ray diffractometer and superconducting quantum interference device. The results show that the crystallinity of Al1-xCuxN thin film gets enhanced significantly after thermal treatment. The saturated magnetic moment of the Al1-xCuxN thin film increases up to 5. 16 emu / cm3 after annealed at 950 ℃under N2 environment. The origin of room temperature ferromagnetism is supposed to be the combined effects of p-d hybridization mechanism and N-related defects.