飞秒激光辐照CuZr非晶合金损伤动力学研究

Study on the damage dynamics of CuZr amorphous alloy nanofilm irradiated by femtosecond laser

摘要:

采用考虑了电子压强梯度的双温分子动力学方法，我们研究了纳米CuZr非晶合金薄膜在脉宽为100 fs，能量密度为0.08~0.16 J/cm2的飞秒激光辐照下的烧蚀动力学过程. 结果表明，低能量密度下，电子压强梯度对靶材的结构损伤过程影响很小. 高能量密度下，电子压强梯度对靶材内部的电子温度和晶格温度演化场产生了显著的影响，CuZr非晶合金薄膜的结构存在皮秒量级的由电子压强梯度诱导的非热烧蚀过程，并且随着能流密度的增大，这一超快的非热烧蚀过程在时间尺度上会得到提前.

Abstract:

We use a two temperature molecular dynamics model considering electronic pressure gradient to investigate the ablation dynamics process of CuZr amorphous alloy nanofilm irradiated by femtosecond laser, in which the fluence is selected from 0.08 to 0.16 and the duration of laser is 100fs. The results indicate that , at low laser fluence, the electronic pressure gradient has a little impact on the structural damage process of the target material. At high laser fluence, the electronic pressure gradient has a significant influence on the evolution of the electron temperature and the lattice temperature field of the internal target material. Under the effect of electronic pressure gradient, the presence of rapid nonthermal ablation process of the structure of CuZr amorphous alloy nanofilm is on the time scale of picosecond, and with the increasing fluence, this ultrafast nonthermal ablation process can be advanced on the timescale.