Research progress of one-dimensional nanomaterials irradiated by heavy ions in the Institute of Modern Physics

The mutual research between charged heavy ions and macroscopic bulk materials has been carried out for many years, and the research results are widely used in the fields of material modification, radiation resistance evaluation of nuclear materials, and reinforcement of electronic components. When the size of the bulk material is reduced to the nanometer level, its acoustic, electromagnetic, thermodynamic and optical properties will change significantly, which leads to the irradiation effect of the nanomaterial will be different from that of the bulk material under the same irradiation conditions. different. In order to study the radiation damage effect of metal nanomaterials, researchers from the Materials Research Center of the Institute of Modern Physics, Chinese Academy of Sciences prepared one-dimensional nanomaterials by the heavy ion track template method.——Gold nanowires are the research object, and the research on the interaction between heavy ions and one-dimensional nanomaterials has been carried out, and the basic physical process and damage mechanism of one-dimensional nanomaterials irradiated by heavy ions has been revealed. The researchers used the heavy ions provided by the 320kV high-charge state ion comprehensive experimental platform of the Institute of Modern Physics to irradiate gold nanowires with different diameters, and used scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM) to analyze the before and after irradiation. The morphology and structure of gold nanowires were characterized and analyzed, and the radiation damage effect of heavy ions on gold nanowires was systematically studied. It is found that three types of crater-like structures with different morphologies can be generated on the surface of nanowires by heavy ion irradiation, and the crater structures with different morphologies are directly related to the positions of the thermal peaks induced by heavy ions in the nanowires. When the thermal peak occurs at a thickness of several atomic layers below the surface of the nanowire, the molten gold in the thermal peak will be adsorbed on the surface of the nanowire through plastic flow, forming a crater-shaped structure; when the thermal peak appears at a position deeper from the surface When , the volume expansion of the molten gold will generate a huge pressure to cause a micro-explosion in the area where the thermal peak is located, resulting in the eruption of the molten gold. When the kinetic energy of the ejected gold is less than the surface adsorption energy of the nanowire, it will be adsorbed on the nanowire to form a crater with protruding particles; otherwise, a crater without protruding particles will be formed. Meanwhile, a large number of sputtered gold nanoparticles were observed around the gold nanowires, and it was found that the average size of the sputtered particles increased with the diameter of the nanowires. In addition, the researchers studied the effect of heavy ion irradiation on the crystal structure of gold nanowires. A large number of stacking fault tetrahedral structures (SFT) were observed by HRTEM, and the relationship between the size distribution of SFT in gold nanowires and the nuclear energy loss of incident ions was given. relationship between. This study extends the research object of heavy ion irradiation from macroscopic bulk materials to one-dimensional nanomaterials, revealing new properties of heavy ion irradiation based on nanomaterials. The research work was supported by the National Natural Science Foundation of China and the Youth Innovation Promotion Association of the Chinese Academy of Sciences. The related research results were published in Nanomaterials.