Bradley R Mark, Sharath Tejas
Departments of Physics and Mathematics, Colorado State University, Fort Collins, Colorado 80523, USA.
Department of Physics, Colorado State University, Fort Collins, Colorado 80523, USA.
Phys Rev E. 2021 Feb;103(2-1):022804. doi: 10.1103/PhysRevE.103.022804.
We study nanoscale pattern formation on the surface of a solid that is bombarded with two diametrically opposed, broad ion beams for ion energies low enough that sputtering can be neglected. We focus on the case in which the angle of ion incidence is just above the threshold angle for pattern formation. The equation of motion at sufficiently long times is derived using a generalized crater function formalism. This formalism also yields expressions for the coefficients in the equation of motion in terms of crater function moments. We find that virtually defect-free ripples with a sawtooth profile can emerge at sufficiently long times. The ripples also coarsen as time passes, in contrast to the near-threshold behavior of ripples in the higher energy regime in which sputtering is significant.
我们研究了在固体表面形成纳米级图案的情况，该固体受到两束沿直径方向相对的宽离子束轰击，离子能量足够低，以至于可以忽略溅射效应。我们关注离子入射角刚好高于图案形成阈值角的情况。利用广义坑函数形式推导了足够长时间下的运动方程。这种形式还根据坑函数矩给出了运动方程中系数的表达式。我们发现，在足够长的时间内，实际上可以出现几乎无缺陷的锯齿形波纹。与溅射显著的高能区中波纹的近阈值行为相反，随着时间的推移，这些波纹也会变粗。
