Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany, EU.
Phys Rev Lett. 2012 Sep 14;109(11):117602. doi: 10.1103/PhysRevLett.109.117602.
The impact of individual slow highly charged ions (HCI) on alkaline earth halide and alkali halide surfaces creates nano-scale surface modifications. For different materials and impact energies a wide variety of topographic alterations have been observed, ranging from regularly shaped pits to nanohillocks. We present experimental evidence for the creation of thermodynamically stable defect agglomerations initially hidden after irradiation but becoming visible as pits upon subsequent etching. A well defined threshold separating regions with and without etch-pit formation is found as a function of potential and kinetic energies of the projectile. Combining this novel type of surface defects with the previously identified hillock formation, a phase diagram for HCI induced surface restructuring emerges. The simulation of the energy deposition by the HCI in the crystal provides insight into the early stages of the dynamics of the surface modification and its dependence on the kinetic and potential energies.
个体慢速高电荷离子（HCI）对碱土卤化物和碱金属卤化物表面的影响会产生纳米级的表面改性。对于不同的材料和冲击能，已经观察到各种各样的地形改变，从规则形状的凹坑到纳米丘。我们提供了实验证据，证明最初在辐照后隐藏的热力学稳定缺陷聚集体的形成，随后在随后的蚀刻中会变成凹坑。发现作为势和射弹动能函数的具有和不具有蚀刻坑形成的区域之间的良好定义的阈值。将这种新型的表面缺陷与先前确定的丘形成相结合，出现了 HCI 诱导的表面重构的相图。通过 HCI 在晶体中的能量沉积的模拟提供了对表面改性动力学及其对动能和势能的依赖的早期阶段的深入了解。
