硅油基底表面铁薄膜的生长机理及表面有序结构

利用直流溅射方法在液体基底(硅油)表面成功制备出金属铁薄膜系统，研究了其生长机理及特征的表面有序结构.实验发现铁薄膜的生长过程与液相基底表面非磁性金属薄膜的情况类似，基本服从二阶段生长模型.连续铁薄膜中可观测到尺寸巨大的圆盘形有序结构，其生长演化与溅射功率、沉积时间和真空环境中的生长时间等实验条件密切相关.实验证明，此类有序结构是在薄膜内应力作用下，铁原子及原子团簇在液体表面自由扩散迁移，并最终在硅油基底表面某些区域成核凝聚所致.在较大溅射功率和沉积时间条件下，圆盘外部区域的铁薄膜中形成周期分布的波纹褶皱，其波长约为10 μm，波峰基本与圆盘的边界平行.进一步研究表明：在沉积过程中，由于沉积铁原子的局域能量作用，导致硅油的表面层结构发生改变而形成一聚合物层；在随后的冷却过程中，聚合物层的强烈收缩使铁薄膜处于很大的压应力场中，促使薄膜起皱形成波纹结构. 关键词： 液体基底 铁薄膜 生长机理 有序结构

Growth mechanism and ordered structures of iron films sputter-deposited on silicone oil surfaces

A series of iron films has been successfully fabricated by deposition on silicone oil surfaces using the DC-magnetron sputtering method, and the growth mechanism and ordered surface morphologies have been systematically studied. It is found that the growth mechanism of the iron films is similar to that of nonmagnetic films on liquid substrates,in accordance with a two-stage growth model. Large disk-shaped patterns (disks) are observed in the continuous films and their growth behaviors are mainly related to the sputtering power, deposition time and growth duration in vacuum. The experiment indicates that the disks may result from the spontaneous, free organization and gathering of the iron atoms and atomic clusters driven by the internal stress. If the sputtering power and deposition time are comparatively large, wavy buckles with a nearly uniform wavelength of about 10 μm are observed in the continuous films, generally aligning parallel to the boundaries of the disks. Further analysis shows that the top surface of the silicone oil is modified to form a soft polymer layer during deposition. Subsequent cooling of the system creates compressive stress in the iron film, which is relieved by buckling to form the wavy structures.