In this paper, we demonstrate that the sputtering of solids by ions of low (<30 keV) and even ultralow energies (<2 keV) is accompanied by nonlinear effects. These nonlinear effects are the result of heating a significant part of the cascades of collisions above the effective melting temperature of the material with the formation of local melts or “thermal spots” (a special case of the thermal spike regime). Nonlinear effects should primarily be observed in dense targets irradiated by heavy and cluster ions. In this paper, the question of the lifetime of such spots and their effect on the emission of secondary particles and the formation of specific surface topography is examined in detail. Another important assumption of the model is the existence of an intermediate ion sputtering regime, in that both linear cascades and thermal spots can exist simultaneously. A phenomenological model based on the effect of a rapid decrease in the cascade volume with a monotonic decrease in the energy of primary ions below 3 keV, which leads to the formation of thermal spots at ultralow energies (<2 keV), is also proposed. The suggested thermal spot model allows us to explain several experimental data that have not yet been explained in the framework of the traditional sputtering models. In particular, a simple explanation is given for the formation of pores in the surface layer during implantation and the formation of a relief on an ion-bombarded surface such as nanodots, pits (holes), and in the form of a foam-like surface. The small stationary concentration of cesium on the surface of the target sputtered by low-energy cesium ions is also explained.

中文翻译：

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固体低能离子溅射中的非线性效应

在本文中，我们证明了由低能量（<30 keV）甚至超低能量（<2 keV）的离子进行的固体溅射具有非线性效应。这些非线性效应是由于将大部分碰撞级联加热到材料的有效熔化温度以上而形成局部熔体或“热点”（热尖峰状态的特殊情况）的结果。非线性效应应首先在重离子和簇离子照射的密集目标中观察到。在本文中，详细研究了此类斑点的寿命及其对次级粒子发射和比表面形貌形成的影响。该模型的另一个重要假设是存在中间离子溅射机制，因为线性级联和热点可以同时存在。还提出了一种现象模型，该模型基于级联体积的快速减小和低于3 keV的一次离子能量单调减少的影响，从而导致在超低能量（<2 keV）处形成热点。建议的热斑模型使我们能够解释传统溅射模型框架中尚未解释的一些实验数据。特别地，给出了关于在植入期间在表面层中形成孔以及在离子轰击的表面（例如纳米点，凹坑（孔））上形成浮雕并且以泡沫状表面的形式的简单解释。 。