热辅助存储磁盘硅掺杂非晶碳薄膜氧化的ReaxFF反应力场分子动力学模拟（英文）

发布时间：2019-01-17 19:15

【摘要】：热辅助磁存储技术是一种提高磁盘存储面密度到1 Tb·in~(-2)的方法,在数据写入过程中的激光局部加热会使磁盘非晶碳薄膜氧化。本文采用Reax FF反应力场分子动力学方法,建立硅掺杂非晶碳(a-C:Si)薄膜在激光诱导氧化的模型,从原子尺度分析a-C:Si薄膜的结构变化、氧化过程,确定了氧化机理以及激光加热次数对氧化的影响规律。a-C:Si薄膜的氧化发生在加热阶段和初始降温阶段,在加热过程中a-C:Si薄膜的体积扩张和降温过程中原子应变引起碳原子团簇,均使薄膜中sp~2碳含量增加。随着加热次数的增加,表面未饱和原子数量减少和氧原子低扩散率使薄膜氧化速率逐渐降低。此外,非晶薄膜的表面缺陷使分子氧成为氧化剂,表面原子剪切应变使Si O O Si链中O O键断裂,重构氧化表面,进而促进a-C:Si薄膜的氧化。
[Abstract]:Thermal assisted magnetic storage is a method to increase the density of disk storage to 1 Tb in~ (-2). The local heating of laser during data writing will oxidize the amorphous carbon film of the disk. The laser induced oxidation model of Si doped amorphous carbon (a-C:Si) thin films was established by using the Reax FF reaction force field molecular dynamics method. The structure changes and oxidation process of a-C:Si films were analyzed at atomic scale. The oxidation mechanism and the influence of laser heating times on the oxidation were determined. The oxidation of a-C:Si thin films occurred in the heating stage and the initial cooling stage. The volume expansion of a-C:Si films during heating and atomic strain induced carbon clusters in the process of cooling increase the content of sp~2 carbon in the films. With the increase of heating times, the number of surface unsaturated atoms decreases and the low diffusivity of oxygen atoms makes the oxidation rate decrease gradually. In addition, the surface defects of amorphous films make molecular oxygen as oxidant, and the surface atomic shear strain leads to the breaking of O / O bond in the Si chain of Si / O / O and reconstructing the oxidized surface, thus promoting the oxidation of a-C:Si films.
【作者单位】：哈尔滨工业大学机电工程学院;
【基金】：supported by the National Natural Science Foundation of China(51405103) China Post-doctoral Science Foundation(2014M551230,2015T80335)~~
【分类号】：TB383.2

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