Knowledge of laser-pulsed processing of ultrathin liquids on solid surfaces is of great importance in advancing the understanding of synthesis, characterization and applications of functional nanofilms. In this work, we performed molecular dynamics simulations coupled with a novel quantitative coarse-grained model to study laser-induced local heating and depletion behaviors of Fomblin Z2000 lubricants. It was found that the Fomblin lubricant films experience severe evaporation and thermodiffusion-related degradation under laser heating. The ultrathin lubricants inevitably lose their frictional resistance under extremely high temperatures and thermal gradients (i.e., up to 990 K and 65.4 K/nm) that are required for FePt media in HAMR systems. The factors that influence the local thermal depletion, such as laser power, spot size, and scanning velocity, were investigated as well. The results clearly show that the laser power has the greatest influence on the relative maximum temperature change and subsequently the severe lubricant film depletion during rapid laser heating, while the spot size and scanning velocity play a relatively weaker role in the laser-induced local thermal instability. The findings in this work are thus believed to provide molecular scale insights into laser-induced local heating and depletion of ultrathin lubricant films from a precise quantitative perspective.

中文翻译：

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激光诱导的超薄PFPE润滑剂的耗尽使用定量粗粒度模型。

固体表面超薄液体的激光脉冲处理知识对于增进对功能纳米膜的合成，表征和应用的理解非常重要。在这项工作中，我们进行了分子动力学模拟，并结合了新颖的定量粗粒度模型，以研究激光引起的Fomblin Z2000润滑剂的局部加热和消耗行为。发现Fomblin润滑膜在激光加热下会经历严重的蒸发和与热扩散相关的降解。超薄润滑剂不可避免地会在HAMR系统中FePt介质所需的极高温度和热梯度（即高达990 K和65.4 K / nm）下失去摩擦阻力。影响局部热损耗的因素，例如激光功率，光斑大小，扫描速度也进行了研究。结果清楚地表明，激光功率对最大相对温度变化以及随后的快速激光加热过程中严重的润滑膜损耗影响最大，而光斑尺寸和扫描速度在激光引起的局部热不稳定性中的作用相对较弱。 。因此，从精确的定量角度来看，这项工作的发现被认为可以提供分子尺度的洞察力，以了解激光诱导的局部加热和超薄润滑剂膜的消耗。而光斑尺寸和扫描速度在激光引起的局部热不稳定性中的作用相对较弱。因此，从精确的定量角度来看，这项工作的发现被认为可以为激光诱导的局部加热和超薄润滑膜的消耗提供分子尺度的见解。而光斑尺寸和扫描速度在激光引起的局部热不稳定性中的作用相对较弱。因此，从精确的定量角度来看，这项工作的发现被认为可以为激光诱导的局部加热和超薄润滑剂膜的耗竭提供分子尺度的见解。