(北京科技大学 材料物理与化学系, 北京 100083)
摘 要: 通过分子束外延(MBE)和脉冲激光沉积(PLD)将1~10个Fe原子层(ML)以楔型(wedge-shape)方式分别沉积到NiO(001)基片上, 并对其进行磁光克尔效应(MOKE)原位测试。 结果表明: 通过MBE这种低能量沉积方式沉积的Fe原子层在Fe/NiO界面处产生了约2 ML的磁死层; 而通过PLD这种较高能量沉积方式沉积的Fe原子层在Fe/NiO界面处产生了约3 ML的磁死层。 X射线光电子能谱(XPS)研究Fe/NiO界面的结果表明: 两种沉积方式都能使Fe原子与单晶NiO在界面处发生化学反应, 这是导致磁死层的一个重要原因; 对于MBE和PLD沉积方式来说, 从靶材上被蒸发或溅射下来到达基片的原子所具有的能量很低, 分别约为0.1 eV和1.0 eV, 反应层较浅; 磁控溅射沉积Fe原子的能量约为几~十几电子伏特, 导致的反应深度约1.5 nm。
关键字: 界面反应; 磁性薄膜; X射线光电子能谱
(Department of Material Physics and Chemistry, University of Science and Technology Beijing, Beijing 100083, China)
Abstract: One to ten Fe monatomic layers (ML) with wedge-shape were deposited on the NiO(001) substrate by molecular beam epitaxial deposition (MBE) and pulse laser deposition (PLD), respectively. Thin films growth were characterized by in-situ analysis based on magneto-optic Kerr effect (MOKE). The results show that the Fe layer gives rise to an about 2 ML magnetic dead layer at the Fe/NiO interface by the method of MBE with low-energy deposition, and the magnetic dead layer is about 3 ML as to the method of PLD with higher-energy deposition. X-ray photoelectron spectroscopy (XPS) analysis indicates that these two deposition ways can both cause the interfacial chemical reactions, which is an important reason for the magnetic dead layer. For MBE and PLD, the atoms evaporated or sputtered off from the target and arrived at the substrate are provided with kinetic energy of about 0.1 eV and 1.0 eV, respectively. Therefore, the interfacial reaction thickness is shallow. The interfacial reaction of the biggest thickness of 1.5 nm is caused by magnetron sputtering.
Key words: interfacial reactions; magnetic film; X-ray photoelectron spectroscopy (XPS)