ABSTRACT

Self-organization is a phenomenon that occurs under certain circumstances with different types of materials – liquids, bulk, and thin films, organic, inorganic or hybrid solids. This unique effect appears as an unusual part of various dynamic processes, such as co-deposition of immiscible phases, or due to modifications by external stimuli, such as thermal annealing or laser irradiation. A significant aspect of this effect is a certain level of energy flow, which creates conditions for the onset of a coordinated re-arrangement that leads to the self-organization of materials. Of interest is the stimulus of bombardment by energetic ions, which can lead (i) to radiation damage to the original structure, but (ii) also to constructive effects – the synthesis of materials with new structural forms and novel properties. The manifestation of a constructive ion irradiation stimulus was investigated also in this paper. Ternary and binary thin films – n-times repeating groups of (Ti/C)_n, (Ti/Sn/C)_n, (Hf/In/C)_n with stoichiometric ratios 2/1 and 2/1/1 prepared by ion beam sputtering, were bombarded using 35 keV or 200 keV Ar⁺ ions to 10¹³ cm⁻² or 10¹⁵ cm⁻² fluence. Irradiation with swift heavy ions to such a high fluence should have a significant impact on the material. In fact, it turned out that the bombardment with Ar⁺ ions led to a pronounced re-arrangement of the inspected multilayers – to disruption of their original structure and self-crystallization of MAX and MXene nanostructures with various (nano-to-meso) size and densities. This effect was attributed to the collision cascade energy transfer, but it is also considered to be due to collective excitation processes. This result may repoint to the importance of ion irradiation for the technology of new materials, which can be otherwise difficult to synthesize in other ways.

摘要

自组织是在某些情况下，使用不同类型的材料（液体，块状和薄膜，有机，无机或杂化固体）会发生的现象。这种独特的效果表现为各种动态过程的不寻常部分，例如不溶混相的共沉积，或者是由于外部刺激（例如热退火或激光辐照）而发生的变化。这种影响的一个重要方面是一定水平的能量流，它为协调重新安排的开始创造了条件，从而导致了材料的自组织。令人感兴趣的是高能离子轰击的刺激，它可能导致（i）辐射破坏原始结构，但（ii）也产生建设性效果–合成具有新结构形式和新特性的材料。本文还研究了建设性离子辐照刺激的表现。三元和二元薄膜–轰击通过离子束溅射制备的化学计量比为2/1和2/1/1的n重复组（Ti / C）_n，（Ti / Sn / C）_n，（Hf / In / C）_n使用35 keV或200 keV Ar ⁺离子达到10 ¹³ cm ^-2或10 ¹⁵ cm ^-2的通量。快速重离子辐照至如此高的通量应该对材料产生重大影响。实际上，事实证明，用Ar ⁺轰击离子导致被检查的多层的显着重新排列-破坏了它们的原始结构以及具有各种（纳米到中观）尺寸和密度的MAX和MXene纳米结构的自结晶。该效应归因于碰撞级联能量传递，但也被认为归因于集体激发过程。该结果可能表明离子辐照对于新材料技术的重要性，否则很难以其他方式进行合成。