高重频飞秒激光诱导磁性镍薄膜产生LIPSS的研究  

The study of LIPSS on magnetic nickel film induced by high repetition femtosecond laser

作　　者：季羽飞 王红蕊 常虹[2] 刘博文[1] 庞冬青[1] 胡明列[1] JI Yufei;WANG Hongrui;CHANG Hong;LIU Bowen;PANG Dongqing;HU Minglie(Ultrafast Laser Laboratory,College of Precision Instrument and Optoelectronics Engineering,Tianjin University,Tianjin 300072,China;School of Physical Science and Technology,Inner Mongolia University,Hohhot 010021,China)

机构地区：[1]天津大学精密仪器与光电子工程学院超快激光实验室,天津300072 [2]内蒙古大学物理科学与技术学院,内蒙古呼和浩特010021

出　　处：《红外与激光工程》2024年第7期101-108,共8页Infrared and Laser Engineering

基　　金：国家自然科学基金项目(62227821)。

摘　　要：飞秒激光诱导周期性表面结构(Laser-Induced Periodic Surface Structures,LIPSS)是使用线偏振激光作用于材料时最常见的一种表面形貌,一直被研究人员广泛关注,但是在磁性薄膜上诱导产生LIPSS的研究仍相对较少,因此研究高重频飞秒激光作用于磁性薄膜材料后材料磁学性质的变化是十分必要的。实验使用中心波长1030 nm、脉冲宽度300 fs、重复频率100 kHz的飞秒激光在厚度为100 nm的镍薄膜上进行线扫描,诱导产生了LIPSS。光学显微镜和电子显微镜图像显示,在高重频飞秒激光的热效应影响下,LIPSS条纹的周期测量值约为989 nm。通过X射线衍射仪和超导量子干涉仪对写有周期性LIPSS结构的样品进行测试并分析,证明了产生LIPSS过程中导致的材料原子重组并没有改变镍膜的颗粒大小和组成成分,飞秒激光作用后的磁性材料的饱和磁化强度也基本与原样保持一致,但其矫顽力发生了明显的变化,笔者认为这是由于加工过程中喷溅出的极少量反铁磁氧化镍颗粒产生的钉扎效应所导致的。Objective Femtosecond laser-induced periodic surface structure(LIPSS) is the most common surface morphology on almost any material after irradiation by a linearly polarized laser, which has been widely studied by researchers. However, research on inducing LIPSS on magnetic thin films using high femtosecond lasers is still relatively limited. The authors used femtosecond laser with central wavelength of 1 030 nm, pulse width of300 fs, and repetition rate of 100 kHz to induce the formation of LIPSS on 100 nm nickel film. The optical microscope and scanning electron microscope images show that affected by the thermal effect of the high repetition femtosecond laser, the measured period of LIPSS stripes is about 989 nm. Through the analysis of experimental data measured by the X-ray diffractometer and SQUID, it was proved that the material atomic recombination caused by the formation process of LIPSS did not change the particle size or composition of the nickel film. The saturation magnetization of the laser-induced magnetic material is also basically consistent with the reference sample, but the coercivity changes significantly. The authors consider that it is due to the pinning effect generated by the little amount of anti-ferromagnetic nickel oxide particles splashed out during the processing.Methods This study used a galvanometer-based femtosecond laser processing system(Fig.1) to produce two grating samples with different periods of LIPSS(Fig.2-3). The period was measured based on the diagrams of the scanning electron microscope(Fig.4), and the X-ray diffraction spectra of the samples were measured by XRD(Fig.5). The hysteresis loops were measured by SQUID(Fig.6, Tab.1), and the calibrated saturation magnetization was calculated(Tab.2).Results and Discussions The SEM measurement shows that the period of LIPSS is about 989 nm, which is caused by the thermal effect of high repetition femtosecond laser. The XRD results show that the particle size and composition of the grating samples is basically the same with the

关 键 词：飞秒激光精密加工 激光诱导周期性表面结构 高重频飞秒激光 磁性材料 饱和磁化强度 

分 类 号：O437[机械工程—光学工程]